In the wake of the GA-06 special election, it’s worth taking a look at just how broad (or narrow) the universe of competitive House districts looks going into 2018. However, defining that universe is tricky. Plenty of political assumptions were upended in the 2016 campaign. The Democrats' impenetrable “blue wall” in the Midwest was breached. Republicans' hold on wealthy, well-educated suburbs was loosened. And, the “Obama coalition”–younger, more diverse voters–once again failed to turn out without Barack Obama on the top of the ticket.  Over 200 counties that supported Obama in 2012 flipped to Trump in 2016. Meanwhile, 30 counties that traditionally vote Republican, including population-heavy Orange County, California, went for Hillary Clinton. 

It’s also hard to gauge how much of what we saw in 2016 was unique to the candidates and the environment and how much can be attributed to something more durable, like a trend line that’s been slowly developing over the past four elections. 

To help tease out the outlier from the trend, my colleague David Wasserman crunched the numbers in all 435 House districts for the 2004, 2008, 2012 and 2016 elections. He separated the results into two groups: 1) recent trend—how did Trump’s performance in 2016 compare with Mitt Romney’s performance in that same CD in 2012 and 2) long-term trend—the average Republican presidential performance in 2012 and 2016 vs. the average GOP presidential nominee’s performance in 2004 and 2008. 

For example, the recent trend in all four Utah districts is Strongly Anti-Trump, but the long-term trend is Stable. This ruby red state didn’t get less Republican in 2016, but it was clearly down on Trump. But, in GA-06, the trend lines are both Strongly Anti-Trump and Strongly Pro-Democratic, which means Trump's poor performance was the culmination of a long-term trend and not just a blip. 

Republican-held Districts that were trending Democratic before Trump and continued that trend in 2016.

We found 27 Republican-held districts that were trending Democratic pre-2016 that continued that trend in 2016. Most are suburban CD’s surrounding fast-growing urban areas like suburban Chicago, Atlanta, Denver and Orange County, California. Many of those Democratic-trending CD’s are in Texas - specifically the Dallas-Fort Worth Metroplex. Again, it’s important to remember that these districts didn’t suddenly become “less Republican” in the Trump era. They have been trending away from the GOP for a while now. 

To be sure, many of these aren’t considered top Democratic targets in 2018. And, “trending” does not mean these seats are actually Democratic-leaning. Just 15 of these 27 districts were carried by Clinton in 2016, while 21 of these CD’s have a Republican PVI, including 4 with a PVI score at or above R+10. However, these are the sorts of districts that may expand the field of competitive contests in the future. 

Republicans in Pro-Dem/Anti-Trump Trending Districts (27)

California-21 David Valadao (R) D+5
California-22 Devin Nunes (R) R+8
California-25 Steve Knight (R) R+2
California-39 Ed Royce (R) R+2
California-45 Mimi Walters (R) R+3
California-48 Dana Rohrabacher (R) R+4
California-49 Darrell Issa (R) R+1
California-50 Duncan D. Hunter (R) R+11
Colorado-6 Mike Coffman (R) D+2
Florida-25 Mario Diaz-Balart (R) R+4
Florida-26 Carlos Curbelo (R) D+6
Florida-27 Ileana Ros-Lehtinen (R) D+5
Georgia-6 Karen Handel (R) R+8
Georgia-7 Rob Woodall (R) R+9
Illinois-6 Peter Roskam (R) R+2
Minnesota-3 Erik Paulsen (D) D+1
Oklahoma-5 Steve Russell (R) R+10
Texas-2 Ted Poe (R) R+11
Texas-3 Sam Johnson (R) R+13
Texas-6 Joe Barton (R) R+9
Texas-7 John Culberson (R) R+7
Texas-22 Pete Olson (R) R+10
Texas-23 Will Hurd (R) R+1
Texas-24 Kenny Marchant (R) R+9
Texas-32 Pete Sessions (R) R+5
Virginia-7 Dave Brat (R) R+6
Virginia-10 Barbara Comstock (R) D+1

Democratic-held Districts that were trending Republican before Trump and continued that trend in 2016.

There aren’t all that many districts that Democrats hold that are getting more Republican.

Most of those seats were lost in the 2010 midterm rout. However, there are still 16 districts that have been trending Republican pre-Trump and continued that GOP trend in 2016. Notably, many are districts that have (or had) a significant manufacturing presence. Democrat Cheri Boustos’ Quad Cities district (IL-17) is home to Caterpillar and John Deere. They build ships in Joe Courtney’s 2nd Congressional district of Connecticut. The former steel manufacturing hub of Gary, Indiana (Pete Visclosky’s IN-01) is also on this list.  

As with the Republican seats above, only a handful-seven-voted for Trump in 2016. But, these are the kinds of districts that can be ripe for a GOP takeover in the right year.

Democrats in Pro-GOP/Pro-Trump Trending Districts (16)

Connecticut-2 Joe Courtney (D) D+3
Illinois-17 Cheri Bustos (D) D+3
Indiana-1 Peter Visclosky (D) D+8
Iowa-2 Dave Loebsack (D) D+1
Massachusetts-1 Richard Neal (D) D+12
Michigan-5 Daniel Kildee (D) D+5
Michigan-13 John Conyers (D) D+32
Minnesota-1 Tim Walz (D) R+5
Minnesota-7 Collin Peterson (D) R+12
Minnesota-8 Rick Nolan (D) R+4
New Hampshire-2 Annie Kuster (D) D+2
Ohio-13 Tim Ryan (D) D+7
Oregon-4 Peter DeFazio (D) D+1
Pennsylvania-17 Matthew Cartwright (D) R+2
Rhode Island-2 Jim Langevin (D) D+6
Wisconsin-3 Ron Kind (D) D+1

The Trump Effect Districts: These are the districts that broke away from their trend lines in 2016 either for or against Trump.

There were 29 Republican-held districts that went from stable/moderately Republican pre-2016, to moderately to strong-anti Trump in 2016. In other words, before 2016, these districts weren’t showing consistent movement away from the party. In the era of Trump, they did.

Not surprisingly, three of those districts are in Arizona, where Trump underperformed Romney by five points. Suburban districts in Kansas City, Philadelphia, Atlanta and St. Louis also make the list. Some are long-time targets: AZ-02, PA-06, PA-07 - while others, like Lamar Smith’s TX-21 (PVI R+10), have never been considered in play. Will Trump be a drag on these incumbents in 2018, or will the overall lean of the district keep these seats in the GOP column?

Republicans in Stable/Pro-GOP but Anti-Trump Trending Districts (29)

Alabama-6 Gary Palmer (R) R+26
Arizona-2 Martha McSally (R) R+1
Arizona-5 Andy Biggs (R) R+15
Arizona-6 David Schweikert (R) R+9
California-4 Tom McClintock (R) R+10
Florida-4 John Rutherford (R) R+17
Georgia-11 Barry Loudermilk (R) R+17
Illinois-14 Randy Hultgren (R) R+5
Indiana-5 Susan Brooks (R) R+9
Kansas-3 Kevin Yoder (R) R+4
Missouri-2 Ann Wagner (R) R+ 8
Nebraska-2 Don Bacon (R) R+4
New Jersey-11 Rodney Frelinghuysen (R) R+3
New Jersey-7 Leonard Lance (R) R+3
Pennsylvania-6 Ryan Costello (R) R+2
Pennsylvania-7 Patrick Meehan (R) R+1
South Carolina-1 Mark Sanford (R) R+10
Texas-10 Michael McCaul (R) R+10
Texas-12 Kay Granger (R) R+18
Texas-17 Bill Flores (R) R+12
Texas-21 Lamar Smith (R) R+10
Texas-25 Roger Williams (R) R+11
Texas-26 Michael Burgess (R) R+18
Texas-31 John Carter (R) R+10
Texas-8 Kevin Brady (R) R+28
Utah-1 Rob Bishop (R) R+26
Utah-2 Chris Stewart (R) R+16
Utah-3 Jason Chaffetz (R) R+25
Utah-4 Mia Love (R) R+13

There were 23 Democratic-held seats that went from being stable or moderately pro-Democratic pre-2016, to moderately pro-Trump in 2016. A good chunk (8) are from Trump’s backyard in New York and New Jersey. These are also some rural and blue collar districts in here from Michigan, Ohio, Rhode Island and Maryland. Hawaii, a state that was never contested during the Obama era for obvious reasons, also made this list.

Democrats in Stable/Pro-Dem but Pro-Trump Trending Districts (23)

Connecticut-3 Rosa DeLauro (D) D+9
Delaware-AL Lisa Blunt Rochester (D) D+6
Florida-13 Charlie Crist (D) D+2
Georgia-2 Sanford Bishop (D) D+6
Hawaii-1 Colleen Hanabusa (D) D+17
Hawaii-2 Tulsi Gabbard (D) D+19
Maine-1 Chellie Pingree (D) D+8
Maryland-2 Dutch Ruppersberger (D) D+11
Michigan-9 Sander Levin (D) D+4
Michigan-12 Debbie Dingell (D) D+14
Nevada-4 Ruben Kihuen (D) D+3
New Jersey-1 Donald Norcross (D) D+13
New Jersey-6 Frank Pallone (D) D+9
New Jersey-9 Bill Pascrell (D) D+16
New York-5 Gregory Meeks (D) D+38
New York-8 Hakeem Jeffries (D) D+36
New York-18 Sean Patrick Maloney (D) R+1
New York-20 Paul Tonko (D) D+7
New York-26 Brian Higgins (D) D+11
Ohio-9 Marcy Kaptur (D) D+14
Rhode Island-1 David Cicilline (D) D+14
South Carolina-6 Jim Clyburn (D) D+19
Vermont-AL Peter Welch (D) D+15

Bottom Line: The baseline assumption is that there are few competitive districts in the House. Based on PVI alone, that’s true. But, there are also a lot of districts that have the potential to become competitive in the future. Some have been quietly trending toward/away from a party and this movement was finally brought to light by Donald Trump’s performance in 2016.  Not all of these districts will be part of the 2018 battleground map. But they should be considered as part of a broader look at the nation’s evolving voting patterns and behavior. 





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