Mike Espy Needs An Unprecedented Swing To Win The Mississippi Runoff

We don’t often see a runoff in a general election, but if Sen. Cindy Hyde-Smith were to lose Mississippi’s Senate runoff on Tuesday, after the two Republican candidates combined to win a sizable majority of the initial vote, that would be even more unusual.

In the first round, Republicans Hyde-Smith and Chris McDaniel combined for a bit less than 58 percent of the vote, while Democrat Mike Espy and one other candidate from his party together won a little more than 42 percent. For Espy to win, the runoff vote has to swing more than 15 points more Democratic than the initial vote margin. But if we look at the five Senate elections since 1990 where an initial round of voting was held on the national Election Day and two candidates advanced to a runoff,1 no challenger has ever come close to outperforming the previous round of voting by the kind of margin Espy would need to win. What’s more, no runoff has ever shifted that much in either party’s direction.

Democrats need a record-setting swing to win Mississippi

Shifts in vote share margin between first election and runoff, in Senate races since 1990 where the first election took place on the national November Election Day in a midterm or presidential cycle

vote share margin
Year State First Election Runoff Swing
1992 GA D+1.6 R+1.3 R+2.9
2002 LA R+2.9 D+3.4 D+6.3
2008 GA R+2.9 R+14.9 R+12.0
2014 LA R+12.3 R+11.9 D+0.4
2016 LA R+25.4 R+21.3 D+4.1
2018 MS R+15.3

In cases where the first election included multiple candidates from the same party (all Louisiana and Mississippi races in the table), the margin is based on the difference in the total vote share between all Democratic and Republican candidates. In some cases, parties had unequal numbers of candidates running, which may have exaggerated the differences in vote share. Some data may not add up due to rounding.

Sources: ABC News, Georgia Secretary of State, Louisiana Secretary of State, UVA Center for Politics, Federal Election Commission

In fact, the biggest swing recorded — 12 points in the 2008 Georgia Senate runoff — favored the incumbent and not the challenger. Of the five previous Senate elections that went to a runoff, four featured incumbents, and in those contests, the swing in party vote share moved in the challenger’s favor only once. In Georgia’s 1992 Senate election, Democratic Sen. Wyche Fowler missed a majority by 1 percentage point in the general election, and in the runoff, challenger Republican Paul Coverdell squeaked out a narrow victory as the margin shifted 3 points in the GOP’s direction.

As for that big swing in Georgia’s 2008 Senate election, it came about in part because of the unprecedented circumstances surrounding the general election. The initial vote took place during Barack Obama’s first presidential bid, which saw African-American voters turn out at much higher rates than usual, both nationally and in Georgia. That turnout did not repeat itself in the runoff, however, and Republican Sen. Saxby Chambliss won re-election by 15 points.

The next-largest shift (and the largest shift in a midterm election) also benefited an incumbent, although it was much smaller. In 2002, four GOP candidates combined for a narrow edge over two Democratic candidates in the initial vote, but Democratic Sen. Mary Landrieu narrowly won the Louisiana Senate runoff by shifting the margin 6 points in a Democratic direction. So a Democrat has moved the needle enough to win a runoff in the Deep South in the recent past, although the politics of Louisiana (and the rest of the region) have shifted further toward the GOP since the early 2000s. Moreover, Landrieu didn’t need nearly as large a swing as Espy does in 2018.

From this admittedly small sample of Senate runoffs, an Espy win looks like a long shot: These races rarely swing by nearly as much as he needs to win, and when they swing at all, it’s more often toward the incumbent than the challenger. Furthermore, the Nov. 6 result in Mississippi looks similar to the 2014 and 2016 contests in Louisiana, which also bodes poorly for Espy. In those races, the GOP candidates combined for a double-digit margin in the first election, and in the runoff, the Democrat only gained a little ground. In that 2014 race, Landrieu was voted out of office after nearly 20 years in the Senate (no incumbent ran in 2016). As Nathaniel Rakich wrote in our preview of the Mississippi runoff, Espy needs today’s electorate to be substantially different from the voters who turned out earlier this month; Espy likely needs a strong turnout from black voters, who lean very Democratic, combined with some apathy among white voters, who are strongly Republican in Mississippi.

Politics Podcast: Will Pelosi Be Replaced?


The FiveThirtyEight Politics podcast crew discusses whether Rep. Nancy Pelosi will be re-elected as Speaker of the House, now that Democrats have won back the majority, and what the opposition to her says about the party. They also look at new election results out of Florida, Georgia and Arizona and reflect on the significance of the “year of the woman.”

You can listen to the episode by clicking the “play” button in the audio player above or by downloading it in iTunes, the ESPN App or your favorite podcast platform. If you are new to podcasts, learn how to listen.

The FiveThirtyEight Politics podcast publishes Monday evenings, with occasional special episodes throughout the week. Help new listeners discover the show by leaving us a rating and review on iTunes. Have a comment, question or suggestion for “good polling vs. bad polling”? Get in touch by email, on Twitter or in the comments.

Something Looks Weird In Broward County. Here’s What We Know About A Possible Florida Recount.

The Florida U.S. Senate race is still too close to call. According to unofficial results on the Florida Department of State website at 11:45 a.m. Eastern on Friday, Nov. 9, Republican Gov. Rick Scott led Democratic Sen. Bill Nelson by 15,046 votes — or 0.18 percentage points. We’re watching that margin closely because if it stays about that small, it will trigger a recount. It’s already narrowed since election night, when Scott initially declared victory with a 56,000-vote lead.

The changing margin is due to continued vote-counting in Broward and Palm Beach counties, two of Florida’s largest and more Democratic-leaning counties. On Thursday evening, the supervisors of elections in the two counties told the South Florida Sun Sentinel that vote counting there was mostly complete. Under Florida law, counties have to report unofficial election results to the secretary of state by Saturday at noon, but Nelson’s campaign is suing to extend that deadline. Scott’s campaign and the National Republican Senatorial Committee are also suing both counties for not disclosing more information about the ongoing count, and Scott called on the Florida Department of Law Enforcement to investigate Broward’s handling of ballots.

Unusually, the votes tabulated in Broward County so far exhibit a high rate of something called “undervoting,” or not voting in all the races on the ballot. Countywide, 26,060 fewer votes were cast in the U.S. Senate race than in the governor race.1 Put another way, turnout in the Senate race was 3.7 percent lower than in the gubernatorial race.

Broward County’s undervote rate is way out of line with every other county in Florida, which exhibited, at most, a 0.8-percent difference. (There is one outlier — the sparsely populated Liberty County — where votes cast in the Senate race were 1 percent higher than in the governor race, but there we’re talking about a difference of 26 votes, not more than 26,000, as is the case in Broward.)

To put in perspective what an eye-popping number of undervotes that is, more Broward County residents voted for the down-ballot constitutional offices of chief financial officer and state agriculture commissioner than U.S. Senate — an extremely high-profile election in which $181 million was spent. Generally, the higher the elected office, the less likely voters are to skip it on their ballots. Something sure does seem off in Broward County; we just don’t know what yet.

One possible reason for the discrepancy is poor ballot design. Broward County ballots listed the U.S. Senate race first, right after the ballot instructions. But that pushed the U.S. Senate race to the far bottom left of the ballot, where voters may have skimmed over it, while the governor’s race appears at the top of the ballot’s center column, immediately to the right of the instructions.

Sun Sentinel reporters talked with a ballot expert, who said that some voters may not have noticed the Senate race (perhaps thinking it was just part of the ballot instructions) and started filling out their ballot with the governor race instead. That theory is supported by a data consultant who’s worked for several political campaigns in Florida, who found that the parts of Broward County that fall in the 24th Congressional District did see higher levels of undervoting than other parts of the county. That might be because the 24th District was uncontested, which according to Florida law means that the congressional race did not appear on the ballot at all. As you can see in the sample ballot above, the congressional race would also appear in the lower-left corner on many ballots, along with the Senate race. In districts where there was no congressional race on the ballot, however, that corner would have looked even emptier, perhaps making it easier for voters to inadvertently skip over the Senate race.

An alternative explanation is that an error with the vote-tabulating machines in Broward County caused them to sometimes not read people’s votes for U.S. Senate. If that’s true, we would probably only find out if there is a manual recount. According to Florida law, any election that’s within half a percentage point (as this one currently is) triggers a machine recount; then, after the machine recount, if the race is within a quarter of a percentage point, it goes to a much more complex manual recount — a.k.a. each ballot is recounted by hand. As long as the machine recount doesn’t change the Senate results too much (barring a surprise in the remaining ballots in Broward and Palm Beach), it looks like that’s where we’re headed. In addition, Republican former Rep. Ron DeSantis and Democratic Tallahassee Mayor Andrew Gillum are separated by just 0.44 points in the governor’s race, so that could go to a machine recount, too.

But recounts rarely change the outcomes of elections. A FairVote analysis found that the average recount from 2000 to 2015 shifted the election margin by an average of just 0.02 percentage points. The largest margin swing was 1,247 votes — coincidentally also coming in Florida, in the 2000 presidential race. If Nelson is going to stage a comeback in the Sunshine State, he’ll almost certainly have to close the gap between him and Scott even more in the next couple of days.

Odds Are, Your Next Governor Will Be A Democrat

In the midterm elections for the House and Senate, Democrats are very likely to win the majority of votes, but they face structural barriers to winning the majority of seats. In the House, for instance, we project that Democrats would need to win the popular vote by somewhere in the neighborhood of 5 to 7 percentage points1 to be favored to actually take control of the chamber, a result of partisan gerrymandering after the 2010 election and Democratic voters’ tendency to cluster in dense, urban districts. And, of course, Congress isn’t the Democrats’ only problem: In the 2016 presidential election, Hillary Clinton won the popular vote by almost 3 million votes but lost the Electoral College.

In gubernatorial races, however, there’s no gerrymandering or Electoral College to worry about. So in some ways, they’ll make for the purest test of whether there really is going to be a “blue wave” this year.

And in FiveThirtyEight’s gubernatorial forecasts, which we (finally!) launched on Wednesday, the gubernatorial news is good for Democrats. They are projected to wind up with governorships in states representing about 60 percent of the U.S. population, compared with 40 percent for Republicans.

True, Democrats will have a hard time winning the majority of states, because the GOP is projected to do well in small states such as Wyoming. But the number of states is a stupid metric: Being the governor of Texas is a hell of a lot more important than being the governor of Vermont. Higher-population states, because they have more seats in the House, will also be more important in the redistricting process that will take place after the 2020 elections, when governors elected this year will still be in office.2

So as our measure of gubernatorial success, we’ll simply be counting up the number of people projected to be under each party’s control. Texas will count 44 times as much as Vermont, because there are 44 times more people there.

Democrats begin with an edge in the population count. Although each party controls seven states from among the 14 governorships that are not up for election this year, the states the Democrats hold are more populous. Specifically, Democrats have about 42 million people under their control — based on the states’ projected populations as of Election Day3 — while the seven Republican states have 26 million people.

In states not on the ballot, Democrats start with a lead

Population in states where governors are not up for re-election

Democratic governor republican governor
State Population* State Population*
North Carolina 10,365,000 Indiana 6,780,000
New Jersey 9,193,000 Missouri 6,217,000
Virginia 8,590,000 Kentucky 4,532,000
Washington 7,423,000 Utah 3,100,000
Louisiana 4,753,000 Mississippi 3,043,000
Montana 1,059,000 West Virginia 1,859,000
Delaware 971,000 North Dakota 754,000
Total 42,354,000 Total 26,285,000

* Projected as of Nov. 6, 2018.


Democrats are poised to add to that advantage on Nov. 6, however. Among the nine states with populations of 10 million or more that will elect new governors next month, Democrats are clear favorites in five (California, New York, Illinois, Pennsylvania and Michigan) and modest favorites in a sixth state (Florida). Republicans are clear favorites only in Texas, where incumbent Greg Abbott is likely to be re-elected. The Ohio and Georgia races are toss-ups.

Democrats are well-positioned in high-population gubernatorial races

Race rating according to FiveThirtyEight’s “Classic” forecast as of Oct. 17

State Population* Solid D Likely D Lean D Toss-Up Lean R Likely R Solid R
California 39,982,000
Texas 28,320,000
Florida 20,992,000
New York 20,266,000
Illinois 13,106,000
Pennsylvania 13,074,000
Ohio 11,887,000
Georgia 10,516,000
Michigan 10,159,000
Arizona 7,023,000
Massachusetts 6,965,000
Tennessee 6,794,000
Maryland 6,148,000
Wisconsin 5,900,000
Minnesota 5,657,000
Colorado 5,598,000
South Carolina 5,046,000
Alabama 4,960,000
Oregon 4,151,000
Oklahoma 3,976,000
Connecticut 3,677,000
Iowa 3,191,000
Arkansas 3,056,000
Nevada 2,995,000
Kansas 2,968,000
New Mexico 2,136,000
Nebraska 1,943,000
Idaho 1,725,000
Hawaii 1,445,000
N.H. 1,367,000
Maine 1,363,000
Rhode Island 1,080,000
South Dakota 878,000
Alaska 751,000
Vermont 637,000
Wyoming 587,000

* Projected as of Nov. 6, 2018.


Republicans will make up ground in small and medium-sized states. Indeed, they’re the favorites (specifically, about 2 in 3 favorites, according to our Classic forecast4) to win a majority of states. But Democrats are highly likely — although by no means certain5 — to govern a majority of the population after the election. Even if Republicans win all the toss-up races and all the races our model currently rates as leaning Democratic, they’d come up a little short of a population majority given the states that Democrats have in hand already. Accounting for each state’s population on a probabilistic basis,6 Democrats currently project to have 194 million people under their control after the election, or about 60 percent of the population, compared with 135 million for Republicans.

Methodology-wise, our gubernatorial forecasts are largely the same as our House and Senate forecasts. There are three versions of our model — Lite, Classic and Deluxe — that blend together different forecasting techniques in different ratios. Specifically, these techniques include

  1. A polling average, after polls are adjusted in various ways.
  2. CANTOR, a system that makes projections based on analysis of polling in similar states.
  3. “Fundamentals,” a regression-based method that evaluates non-polling factors such as fundraising that predict election outcomes.
  4. Expert ratings, such as those put together by the Cook Political Report.

In all versions of our forecast, however, polling is by far the largest ingredient in states where there’s a lot of polling. For more detail on our gubernatorial forecasts, including how they differ from our congressional forecasts, see here.

Perhaps the most important difference between gubernatorial races and congressional ones is that partisanship is much less of a factor in governorships. Specifically, it’s only about one-third as important — so, for example, a state that’s typically 15 percentage points more Republican than the country overall in congressional races would only be about 5 points GOP-leaning in gubernatorial races. As a consequence of this, incumbents tend to be favored even when they come from “opposite-colored” states. Republicans Larry Hogan of Maryland and Charlie Baker of Massachusetts are heavy favorites to win re-election despite being in deeply blue states, for example — not just according to the polls, which have them well ahead, but also according to the fundamentals component of our forecast.

On the flip side, few things are truly inevitable in gubernatorial races, especially in states without incumbents. Democrats are competitive in Oklahoma, for example, while Republicans have a fighting chance in Connecticut, despite it being a blue state in a blue year.

How different versions of our governors forecast compare

As of Oct. 17

Inputs Forecasts
Hawaii D+23.2 D+25.8 D+38.7 D+32.3 D+24.3 D+31.4 D+31.7
New York D+20.0 D+20.7 D+26.2 D+24.6 D+20.0 D+22.1 D+22.9
Rhode Island D+11.2 D+22.2 D+33.5 D+7.5 D+11.2 D+19.5 D+15.5
California D+15.2 D+10.0 D+32.0 D+23.2 D+15.2 D+18.4 D+20.0
Pennsylvania D+14.6 D+14.4 D+18.4 D+16.4 D+14.6 D+15.4 D+15.8
Illinois D+17.9 R+4.6 R+9.3 D+12.9 D+17.9 D+12.7 D+12.7
Michigan D+11.0 D+4.1 D+14.7 D+9.3 D+11.0 D+11.6 D+10.8
Maine D+7.4 D+5.3 D+18.0 D+2.3 D+7.4 D+11.3 D+8.3
Colorado D+7.7 D+3.5 D+15.4 D+7.5 D+7.6 D+10.4 D+9.4
Minnesota D+7.9 D+5.1 D+17.4 D+11.1 D+7.9 D+10.2 D+10.5
Iowa D+4.9 D+2.0 D+14.7 D+0.8 D+4.9 D+8.0 D+5.6
Oregon D+4.4 D+18.0 D+14.0 D+5.3 D+4.4 D+7.9 D+7.0
New Mexico D+6.2 D+5.0 D+10.5 D+7.5 D+6.2 D+7.4 D+7.4
Connecticut D+5.3 D+5.7 D+8.5 D+5.3 D+5.3 D+6.2 D+5.9
Florida D+3.7 0.0 D+0.8 D+2.3 D+3.7 D+3.2 D+2.9
Wisconsin D+5.1 R+8.1 R+7.6 D+0.8 D+5.1 D+2.2 D+1.8
Georgia R+0.8 R+2.3 D+0.1 R+0.6 R+0.8 R+0.7 R+0.7
Nevada R+1.0 D+2.3 R+1.4 D+2.3 R+1.0 R+1.1 D+0.1
Ohio R+0.6 D+1.3 R+4.6 R+0.6 R+0.6 R+1.3 R+1.1
Kansas D+0.3 R+5.0 R+9.1 R+2.9 D+0.3 R+2.4 R+2.5
Oklahoma R+3.4 R+10.5 R+12.1 R+5.9 R+3.4 R+6.4 R+6.2
South Dakota R+0.6 R+7.7 R+16.4 R+3.7 R+4.6 R+10.9 R+8.5
Arizona R+10.5 R+12.1 R+18.4 R+11.3 R+10.5 R+11.5 R+11.4
Alaska R+19.6 R+2.3 R+0.6 R+6.9 R+19.6 R+12.3 R+10.5
Vermont R+12.2 D+0.3 R+15.7 R+22.5 R+5.5 R+13.4 R+16.4
Tennessee R+16.6 R+7.7 R+6.0 R+14.9 R+16.6 R+14.3 R+14.5
Idaho R+11.8 R+10.0 R+18.0 R+21.9 R+11.0 R+15.0 R+17.3
N.H. R+14.0 R+8.0 R+20.8 R+7.7 R+14.0 R+16.1 R+13.3
South Carolina R+18.9 R+4.0 R+13.0 R+18.2 R+18.9 R+16.1 R+16.8
Alabama R+19.1 R+7.9 R+16.3 R+21.5 R+15.1 R+17.1 R+18.6
Maryland R+18.8 R+0.6 R+15.5 R+11.3 R+18.8 R+17.6 R+15.5
Texas R+19.2 R+14.8 R+17.1 R+21.6 R+19.2 R+18.9 R+19.8
Nebraska R+26.7 R+22.2 R+23.3 R+26.7 R+22.7 R+22.9
Wyoming R+23.6 R+25.2 R+25.0 R+23.6 R+25.1 R+25.0
Massachusetts R+36.5 D+1.5 R+19.8 R+28.7 R+36.5 R+29.3 R+29.1
Arkansas R+36.5 R+17.7 R+22.7 R+29.7 R+35.6 R+30.4 R+30.1

We’ll cover the most interesting gubernatorial races on an individual basis in subsequent updates, but here are a few comments about races that I know people will have questions about. Democrats Andrew Gillum of Florida and Stacey Abrams of Georgia are striving to become the first African-American governors of their respective states and the first elected anywhere in the South since Douglas Wilder of Virginia in 1989. Gillum has had a small but fairly consistent lead in the polls, and our model gives him a 70 percent chance (about 7 in 10) of winning. Abrams is in a toss-up race that tilts ever-so-slightly toward her Republican opponent, Brian Kemp. The race is close enough that voter registration protocols in Georgia, which Kemp oversees as secretary of state, could make the difference. (Check out my colleague Perry Bacon Jr.’s article on these races for more detail.)

Although there generally isn’t a big conflict between polls and fundamentals in our gubernatorial forecasts, there are a couple of high-profile races where fundamentals nudge the forecast toward the GOP. In Wisconsin, incumbent Republican Scott Walker trails Democrat Tony Evers by 5 points in our polling average, but the fundamentals think he “should” narrowly win re-election. The Classic version of our model evaluates this race as leaning Democratic, but with Walker having a better chance than polls alone would suggest. And in Kansas, where the controversial Republican secretary of state, Kris Kobach, is running, polls show a true dead heat against Democrat Laura Kelly, but the model classifies the race as leaning Republican on the basis of the fundamentals.

Why The House And Senate Are Moving In Opposite Directions

At first, I was a little skeptical of the narrative that Justice Brett Kavanaugh’s confirmation process could send the House and Senate moving in opposite directions. Usually in politics, a rising tide lifts all boats — so whichever party benefited from the Supreme Court nominee’s confirmation would expect to see its fortunes improve in both its best states and districts and its worst ones.

But a House-Senate split is exactly what we’re seeing in the FiveThirtyEight forecast. Democratic prospects in the Senate are increasingly dire, having fallen to about 1 in 5. Indeed, it’s been hard to find any good news for Democrats in Senate polling lately. In the House, by contrast, their opportunity is holding up relatively well. In fact, Democrats’ chance of taking the House has ticked back upward to about 4 in 5, having improved slightly from around 3 in 4 immediately after Kavanaugh was confirmed. And while district-by-district House polling has been all over the place lately, Democrats’ position has improved slightly on the generic congressional ballot.

On the surface, you might reason that House and Senate battlegrounds aren’t that different from one another. Yes, the most competitive Senate races this year are in really, really red states. Specifically, the average competitive Senate race, weighted by its likelihood of being the decisive state in determining the majority according to FiveThirtyEight’s tipping-point index, is 16 percentage points more Republican than the country overall.1 But the average competitive House district is also pretty red: 8 points more Republican than the country overall, weighed by its tipping-point probability.

The more time you spend looking at the battlegrounds in each chamber, however, the more you’ll come to two important conclusions:

  1. The House and Senate battlegrounds really aren’t that much alike. In several important respects, in fact, they’re almost opposite from one another. For example, House battlegrounds are more educated than the country overall, while Senate ones are less so.
  2. The Democrats’ map in the House is fairly robust, because they aren’t overly reliant on any one type of district. (This stands in contrast to the Senate, where most of the battlegrounds fit into a certain typology: red and rural). While House battlegrounds are somewhat whiter, more suburban and more educated than the country overall, there are quite a few exceptions — enough so that Democrats could underperform in certain types of districts but still have reasonably good chances to win the House. This differs from Hillary Clinton’s position in the Electoral College in 2016, in which underperformance among just one group of voters in one region — white working-class voters in the Midwest — was enough to cost her the election.

So let’s look in more detail at the characteristics of the House and Senate battlegrounds, starting with some basics: their geographic region (as according to the U.S. Census Bureau) and whether they’re incumbent-held or open-seat races. In the series of charts that follow, I’ll show what these characteristics look like in an unweighted average of all 435 congressional districts, and compare that to what’s happening in battlegrounds. (Rather than handpick the “battleground” contests, I’m weighting all races by their tipping-point probabilities in the House and the Senate; contests more likely to prove decisive have outsized sway in the calculation.)

How House and Senate battlegrounds compare based on incumbency and geography

Chance that a race will have a certain characteristic

Characteristic All congressional districts House tipping-point districts* Senate tipping-point states*
Democratic incumbent 40% 6% 46%
Republican incumbent 46 71 29
No incumbent 14 25 25
Characteristic All congressional districts House tipping-point districts Senate tipping-point states
Northeast 18% 19% 2%
Midwest 22 27 32
South 37 27 41
West 23 27 25

*Weighted by tipping-point probability, which is the likelihood that a particular state or district is decisive in determining majority control. Tipping-point determinations are as of 12 p.m. on Oct. 13.

One obvious but overlooked difference between the House and the Senate is that Democratic incumbents have very little exposure in the House but a ton of it in the Senate. For instance, there’s a 46 percent chance that the tipping-point race in the Senate will be one featuring a Democratic incumbent, but only a 6 percent chance for the House. Just the reverse is true for Republicans; they have tons of vulnerable incumbents in the House but few in the Senate. What this means is that, other factors held equal, things that reduce the incumbency advantage will tend to hurt Democrats in the Senate but help them in the House. If, for instance, the Kavanaugh hearings turned the public further against incumbent politicians in both parties, that could contribute to the increasing divergence we’re seeing between the House and Senate forecasts.

Geographically, the competitive House races are almost evenly divided between the four major Census Bureau regions. This is part of what makes Democrats’ map robust: Even if they completely flopped in one of these regions, they could still narrowly win the House by performing to the model’s expectations in the other three. Note, however, that relative to population, the South is slightly underrepresented among the competitive House districts — it represents 37 percent of congressional districts overall but 27 percent of the competitive ones. That’s probably a good thing for Democrats because their coalitions in the South tend to rely on racial minorities and on younger voters — groups that don’t turn out as reliably in midterms as they do in presidential elections.

By contrast, there’s a 41 percent chance that the tipping-point state in the Senate will be in the South. And whereas the Northeast is fairly important to the House map, with a number of competitive races in New York, New Jersey and Pennsylvania, there’s almost nothing interesting happening in the Northeast on the Senate side of the ledger.

Next, here are the political characteristics of competitive districts, based on FiveThirtyEight’s partisan lean index and on whom they voted for in 2012 and 2016. (To make for an apples-to-apples comparison between the House and the Senate, the statistics for Senate races in these next two charts are based on congressional districts within states with competitive Senate races rather than the states overall. For instance, if Tennessee has an 11 percent chance of being the tipping-point state in the Senate, that 11 percent chance is divided between the nine congressional districts in Tennessee to estimate how important individual congressional districts are toward determining Senate control.)

How House and Senate battlegrounds compare based on recent voting patterns

Chance that a race will have a certain characteristic

Characteristic All congressional districts House tipping-point districts* Senate tipping-point districts*
Obama-Clinton 39% 15% 27%
Obama-Trump 5 17 4
Romney-Clinton 3 17 2
Romney-Trump 52 51 67
Characteristic All congressional districts House tipping-point districts* Senate tipping-point districts*
Very Democratic† 32% <1% 16%
Competitive 29 82 21
Very Republican† 39 18 63

* Weighted by tipping-point probability, which is the likelihood that a particular state or district is decisive in determining majority control. For the Senate, statistics are compiled on a district-by-district basis but weighted based on the probability that the state will be decisive to Senate control. Tipping-point determinations are as of 12 p.m. on Oct. 13.

† At least 10 points more Democratic or Republican than the country overall.

It’s true that House battlegrounds are Republican-leaning — but for the most part, they’re Republican-leaning and not much more than that. Only 18 percent of competitive House races have a partisan lean of R+10 or better for the GOP, for instance. By contrast, weighted by their importance to determining the outcome of the Senate, 63 percent of competitive districts are at least R+10. Romney-Clinton and Obama-Trump districts — that is, districts that split their vote between the past two presidential elections — are quite important in the House but not really a factor in the Senate.

Finally, here’s what competitive districts look like based on three characteristics that are increasingly predictive of voting behavior: race, education and urbanization.

How House and Senate battlegrounds compare based on key demographics and urbanization

Chance that a race will have a certain characteristic

Characteristic All congressional districts House tipping-point districts* Senate tipping-point districts*
High education (>=35% bachelor’s degrees) 28% 37% 13%
Medium education 35 41 43
Low education (<=25% bachelor’s degrees) 37 22 45
Characteristic All congressional districts House tipping-point districts* Senate tipping-point districts*
<50% non-Hispianic white 29% 18% 24%
50-80% non-Hispanic white 48 51 38
>80% non-Hispanic white 23 30 38
Characteristic All congressional districts House tipping-point districts* Senate tipping-point districts*
Urban (>2500 people per square mile) 21% 8% 14%
Suburban (500-2500 people per square mile) 23 29 14
Exurban (100-500 people per square mile) 31 39 26
Rural (<100 people per square mile) 25 24 46

*Weighted by tipping-point probability, which is the likelihood that a particular state or district is decisive in determining majority control. For the Senate, statistics are compiled on a district-by-district basis but weighted based on the probability that the state will be decisive to Senate control. Tipping-point determinations are as of 12 p.m. on Oct. 13.

I’ve defined high-education districts as those where at least 35 percent of the adult population has a bachelor’s degree. By that measure, 28 percent of congressional districts in the country overall are highly-educated. But 37 percent of the House battleground districts are highly-educated. By contrast, only 13 percent of the districts that are most important to Senate control have high education levels.

Racially, both House and Senate battlegrounds are whiter than the country as a whole, but the skew is worse in the Senate: 38 percent of districts most important to Senate control are at least 80 percent non-Hispanic white, compared to just 23 percent of districts in the country overall.

Lastly, competitive House districts are concentrated in the suburbs and exurbs (defined based on population density), which make up about half of congressional districts overall but closer to two-thirds of competitive ones in the House. Suburban and exurban districts are quite unimportant to the Senate, however, where the key races are disproportionately based on rural states or in states such as Nevada with a mix of urban and rural areas with little in between.

I’m not going to go on for too much longer because I hope those numbers really speak for themselves. I suppose I had some intuition about how different House and Senate battlegrounds are different from one another — but that intuition didn’t match how sharp the differences are in the data.

Six Districts The GOP Appears To Have Abandoned — And Maybe Two More It Should

Welcome to our Election Update for Wednesday, Oct. 10!

As of 9:20 a.m. Eastern time, Republicans have a 4 in 5 chance (80 percent) of holding the Senate, according to our Classic forecast. The situation is much more dire for the GOP in the House, where Democrats have a 7 in 9 chance (78 percent) of taking control. They are so dire in some GOP-held districts, in fact, that national Republicans have begun pulling their resources or never invested them in the first place — effectively ceding those seats to Democrats, presumably so that the GOP can bolster more winnable districts.

Why take such a drastic step? Usually, it’s because party elders believe the seat is already lost. But parties don’t always show the best judgment about these things, so we thought we would compare the seats that Republicans have given up on with the seats most likely to flip to Democrats in our model. And what we found was that Republicans are indeed picking their battles wisely, at least based on what we know right now.

Daily Kos Elections is tracking House districts that either party appears to have conceded. According to its data, there are six Republican-held districts that both the National Republican Congressional Committee and the Congressional Leadership Fund1 have opted out of: the California 49th, Iowa 1st, New Jersey 2nd, Pennsylvania 5th, Pennsylvania 6th and Pennsylvania 17th.2 (By contrast, national Democrats haven’t abandoned any Democratic-held districts so far, according to the Daily Kos list.) Below are the eight Republican-held districts that our model says are most likely to fall to Democrats, as of 9:20 a.m. Eastern on Wednesday.

Where the GOP pulls the plug, Democrats have better odds

Republican-held districts where Democrats have the highest chances of winning, according to the Classic model of the FiveThirtyEight 2018 House forecast, as of 9:20 a.m. Eastern time on Oct. 10

Democratic candidate Republican candidate
District Name Chance of Winning Name Chance of Winning
PA-5 Mary Gay Scanlon >99.9% Pearl Kim <0.1%
PA-6 Chrissy Houlahan 98.6 Greg McCauley 1.4
NJ-2 Jeff Van Drew 97.6 Seth Grossman 2.4
IA-1 Abby Finkenauer 97.5 Rod Blum 2.5
PA-7 Susan Wild 96.7 Marty Nothstein 3.3
AZ-2 Ann Kirkpatrick 95.3 Lea Marquez Peterson 4.7
CA-49 Mike Levin 93.7 Diane Harkey 6.4
PA-17 Conor Lamb 89.4 Keith Rothfus 10.6

Our model generally agrees with top Republicans’ assessments: All six of the districts that Daily Kos has tracked make our list as well. Republicans are almost certainly correct to give up hope about the Pennsylvania 5th, which (along with every other district in the state) was redrawn in court-ordered redistricting this year; it is now 26 percentage points more Democratic-leaning than the country as a whole.3 The Pennsylvania 6th also got bluer, but the real death knell to the GOP came when incumbent Rep. Ryan Costello backed out of his re-election campaign, leaving his long-shot primary challenger as the only Republican candidate. National Republicans abandoned the New Jersey 2nd District after their candidate linked to a white supremacist website, and in the Iowa 1st, Rep. Rod Blum trails by a wide margin in the polls amid an ethics scandal.

You may have noticed that two of the eight districts in our table aren’t on the Daily Kos list. That’s because Republicans apparently haven’t backed away from them yet — but maybe they should. The Arizona 2nd (which typically plays host to some of the closest congressional races in the country) and the Pennsylvania 7th (another redrawn seat) are strong Democratic bets by our calculations — even stronger than the California 49th and Pennsylvania 17th. But Republicans better not give up on too many seats; each one they triage lowers the number of competitive districts Democrats have to win to take back control of the House. But remember: There’s nothing stopping the GOP from jumping back into any of these races at any time between now and Nov. 6, so nothing is yet lost for good.