Pres Winners House of Reps Trump-Era Elections 2012 2016 # R Seats # D Seats # Regular RE Win Rate # Special SE Win Rate Romney Trump 206 3 56 2% 52 25% Romney Clinton 15 0 9 44% 3 33% Obama Trump 12 9 5 80% 7 71% Obama Clinton 8 182 69 91% 25 96%

For an introduction to these data, see my last post. A few notes:

I’ve added results from the February 27 special elections, when Dems flipped two more state legislative seats and overperformed (but lost) in a third seat.

It’s not straightforward to incorporate the results of Pennsyvlania’s redistricting (which is still being challenged in court), so the above table is valid only for the 115th Congress. The new maps eliminated two Romney-Trump districts and two Romney-Clinton districts, and created four new Obama-Clinton districts. The notion of incumbency doesn’t really make sense, as the districts themselves have changed. But here is how the seats will look for the 2018 midterms:



Pres Winners House of Reps (after PA redistrict) 2012 2016 Total Seats D Seats

(w/o PA) R Seats

(w/o PA) PA seats Romney Trump 207 3 195 9 Romney Clinton 13 13 0 0 Obama Trump 21 11 9 1 Obama Clinton 194 178 8 8

Introduction

Today, I’ll be talking about Romney-Clinton districts (those won by Mitt Romney in 2012 and Hillary Clinton in 2016). Flipping Romney-Clinton districts has formulated a major part of the Democratic strategy for winning the House in 2018. One obvious reason: Democrats have nowhere to go but up, as every single one of the 15 Romney-Clinton Congressional Districts is represented by a Republican.

Moreover, these districts are typically well-educated and have already shown sufficient antipathy to Trump to vote against him in 2016. The thinking goes: they are full of pissed-off, educated suburban moderates, who are going to turn out in 2018 to take their vengeance against the Republicans.

Except here’s the thing: Democratic performance in regular and special elections in Romney-Clinton districts has been mixed. As you can see above, Democrats have lost there more than they have won, taking a total of five of the 12 regular and special elections in Romney-Clinton districts since Trump took office. On the positive side, three of these victories were state legislative seat flips. But, surprisingly, Democrats have actually done better in Obama-Trump districts. There have also been 12 regular and special elections in Obama-Trump districts, and 10 of these have gone to the Democrats (although only two were seat flips).

Are Democrats too bullish on Romney-Clinton districts? Is there anything they can do to run more effectively in them? In this post, I’ll focus on how these Congressional districts are distinct from other Republican-held CDs — and a few ways in which they are similar, too. In Part II, I’ll discuss lessons from Trump-era election results in Romney-Clinton state legislative districts.

How are these CDs Different?

There are 15 Romney-Clinton CDs (including two that have been altered by PA redistricting). These districts have deep Republican roots but a strong aversion to Trump, driven at least partially by higher levels of education than most Republican-held districts. Here are a few ways in which they are atypical of Republican-held Congressional districts.

Presidential Vote Swing

CD Incumbent Obama Margin Clinton Margin Pres Margin Shift AZ-02 Martha McSally -2% 5% 6% CA-25 Steve Knight -2% 7% 9% CA-39 Ed Royce -4% 9% 12% CA-45 Mimi Walters -12% 5% 17% CA-48 Dana Rohrabacher -12% 2% 13% CA-49 Darrell Issa -7% 8% 14% IL-06 Peter Roskam -8% 7% 15% KS-03 Kevin Yoder -10% 1% 11% NJ-07 Leonard Lance -6% 1% 7% PA-06 Ryan Costello -3% 1% 3% PA-07 Pat Meehan -2% 2% 4% TX-07 John Culberson -21% 1% 23% TX-23 Will Hurd -3% 3% 6% TX-32 Pete Sessions -16% 2% 17% VA-10 Barbara Comstock -2% 10% 12% Median R-Held CD: -4%

The presidential margin shifts in these districts are, by definition, positive. But it’s worth noting that most of these shifts are quite large in magnitude, with the median at about 11 percentage points. Below, we plot the distribution of vote shifts in Romney-Clinton districts versus all other Republican-held CDs. As we can see, the Romney-Clinton districts’ shifts are quite extreme relative to most other Republican-held districts.

Ticket Splitting

These districts elected Clinton and a Republican Congressperson simultaneously, so it should be no surprise that they have abnormally high rates of ticket splitting.

While exact ticket splitting rates cannot be directly computed, we use the difference between Clinton’s margin and the Democratic congressional candidate’s margin as a rough proxy for ticket splitting. Note that this number will overestimate the percent of ballots that actually split tickets, due to third party voting and incomplete ballots. Results are given below (Democrats didn’t run a candidate in TX-07 even as Clinton was winning the district, so that race is marked uncontested):

CD Incumbent Clinton Margin 2016 House Margin House Vote Differential AZ-02 Martha McSally 5% -14% -19% CA-25 Steve Knight 7% -6% -13% CA-39 Ed Royce 9% -14% -23% CA-45 Mimi Walters 5% -17% -23% CA-48 Dana Rohrabacher 2% -17% -18% CA-49 Darrell Issa 8% -1% -8% IL-06 Peter Roskam 7% -18% -25% KS-03 Kevin Yoder 1% -11% -12% NJ-07 Leonard Lance 1% -11% -12% PA-06 Ryan Costello 1% -15% -15% PA-07 Pat Meehan 2% -19% -21% TX-07 John Culberson 1% -12% -14% TX-23 Will Hurd 3% -1% -5% TX-32 Pete Sessions 2% U U VA-10 Barbara Comstock 10% -6% -16% Median R-Held CD: -8.1%

With the exceptions of Issa and Hurd, these Republicans ran further ahead of Trump than the median Republican Congressperson. Each had been in the House for at least two years as of 2016, and incumbency likely played a role. But these Republicans are also strong contenders: they were able to motivate a substantial share of the electorate to vote for them, even as those voters were turning against Trump.

Income and Education

These districts differ from other Republican-held districts in two key demographics: they are typically higher income and better educated.

CD Incumbent Median Income Percent College Educated AZ-02 Martha McSally $49,072 34.0% CA-25 Steve Knight $75,367 27.8% CA-39 Ed Royce $85,188 41.6% CA-45 Mimi Walters $97,356 56.0% CA-48 Dana Rohrabacher $88,903 44.6% CA-49 Darrell Issa $80,877 44.0% IL-06 Peter Roskam $97,387 52.2% KS-03 Kevin Yoder $71,562 47.4% NJ-07 Leonard Lance $106,896 51.3% PA-06 Ryan Costello $82,139 43.2% PA-07 Pat Meehan $85,881 43.4% TX-07 John Culberson $71,183 50.7% TX-23 Will Hurd $51,293 21.7% TX-32 Pete Sessions $70,119 43.4% VA-10 Barbara Comstock $120,384 54.3% Median R-Held CD: $53,996 Median R-Held CD: 27.1%

All but two districts (AZ-02 and TX-23) have incomes higher than the median R-held CD, and all but one (TX-23) have higher levels of college education. This largely fits our intuition around these districts — that they are disproportionately populated with Rockefeller Republicans. The 2016 election was bifurcated on educational attainment, and college-educated voters — particularly turned off by the racist and misogynist undercurrent of Trump’s campaign — voted against Trump at very high rates. The distributional differences can be seen in more detail in the plots below.

SALT Deduction Rate

The GOP tax bill caps State and Local Tax (SALT) deductions at $10,000 — a provision that is expected to hit voters in high-tax districts particularly hard. Below, we provide the percent of taxpayers in each district taking the SALT deduction, as sourced from the Tax Policy Center:

CD Incumbent Salt Deduction Rate AZ-02 Martha McSally 29% CA-25 Steve Knight 42% CA-39 Ed Royce 40% CA-45 Mimi Walters 46% CA-48 Dana Rohrabacher 42% CA-49 Darrell Issa 42% IL-06 Peter Roskam 49% KS-03 Kevin Yoder 38% NJ-07 Leonard Lance 53% PA-06 Ryan Costello 42% PA-07 Pat Meehan 45% TX-07 John Culberson 28% TX-23 Will Hurd 20% TX-32 Pete Sessions 27% VA-10 Barbara Comstock 52% Median R-Held CD: 27%

All but two districts (TX-23 and TX-32) have above-average SALT rates. This isn’t surprising given the geographic distribution of these CDs — five are in California and one in New Jersey, both of which have particularly high state taxes. The relatively high incomes in these districts also contributes to their high SALT deduction rates.

Notably, all but three of the Romney-Clinton representatives voted for the tax bill (the holdouts were Issa, who is not running for reelection; as well as Lance and Rohrabacher). Their voters

Nonwhite Population

Lastly, the populations of these CDs are somewhat less white than the typical R-held Congressional district:

CD Incumbent Percent White

(Non-Hispanic) AZ-02 Martha McSally 69% CA-25 Steve Knight 50% CA-39 Ed Royce 37% CA-45 Mimi Walters 58% CA-48 Dana Rohrabacher 62% CA-49 Darrell Issa 65% IL-06 Peter Roskam 82% KS-03 Kevin Yoder 77% NJ-07 Leonard Lance 77% PA-06 Ryan Costello 88% PA-07 Pat Meehan 88% TX-07 John Culberson 51% TX-23 Will Hurd 29% TX-32 Pete Sessions 58% VA-10 Barbara Comstock 69% Median R-Held CD: 80%

All but three districts (PA-06, PA-07, and IL-06) have a lower white percentage of the population than the median Republican Congressional district. Among the remaining CDs, two are majority nonwhite: TX-23, which is majority Hispanic, and CA-39, which has large Asian and Hispanic populations.

How are these CDs Not Different?

Incumbent Congressional Votes

Given that their districts voted for Clinton, one might assume these Republican Congresspeople are much more moderate than the typical Republican. But voting patterns tell a different story. We make use of the DW-Nominate scores aggregated at Voteview, which provide an estimate of how liberal or conservative a lawmaker is, based on his or her voting patterns. More positive values correspond to more conservative votes. Below, we give the nominate score for each Republican along with his or her percentile rank among Republicans in the caucus.

CD Incumbent Nominate Score AZ-02 Martha McSally 0.336 (17%) CA-25 Steve Knight 0.404 (32%) CA-39 Ed Royce 0.662 (87%) CA-45 Mimi Walters 0.425 (34%) CA-48 Dana Rohrabacher 0.627 (82%) CA-49 Darrell Issa 0.505 (53%) IL-06 Peter Roskam 0.433 (36%) KS-03 Kevin Yoder 0.563 (67%) NJ-07 Leonard Lance 0.334 (16%) PA-06 Ryan Costello 0.217 (2%) PA-07 Pat Meehan 0.22 (3%) TX-07 John Culberson 0.503 (52%) TX-23 Will Hurd 0.392 (30%) TX-32 Pete Sessions 0.586 (73%) VA-10 Barbara Comstock 0.273 (10%) Median R: 0.497

The data here is somewhat surprising. While incumbents like Comstock, Costello, Meehan, and Lance are all notably moderate, folks like Royce, Rohrabacher, Sessions, and Yoder are quite extreme. The overall distribution of DW-Nominate scores is only slightly to the left of the distribution for the remainder of the Republican caucus:

Midterm Voter Participation

Since college educated voters are more likely to participate in midterm elections, we might assume that the Romney-Clinton CDs would see higher rates of voter participation in midterms. But if we estimate the percent of voters who cast a ballot in 2014 (as a proportion of all adult residents of the CD), we find that this is not the case:

CD Incumbent 2014 Voter Participation AZ-02 Martha McSally 39% CA-25 Steve Knight 23% CA-39 Ed Royce 25% CA-45 Mimi Walters 31% CA-48 Dana Rohrabacher 31% CA-49 Darrell Issa 30% IL-06 Peter Roskam 45% KS-03 Kevin Yoder 43% NJ-07 Leonard Lance 32% PA-06 Ryan Costello 39% PA-07 Pat Meehan 43% TX-07 John Culberson 28% TX-23 Will Hurd 23% TX-32 Pete Sessions 30% VA-10 Barbara Comstock 43% Median R-Held CD: 34%

2014 voter participation was broadly similar to other Republican-held congressional districts, and was notably lower in some of the more diverse CDs (TX-23, CA-39, CA-25, TX-07). This reflects another well-known pattern: nonwhite voters have historically been less likely to cast ballots in the midterms. Hence, the high rate of college education in the Romney-Clinton CDs seems to be at least partially cancelled out by the greater nonwhite share of the electorate, yielding historical midterm voter participation rates similar to other Republican districts.