2018 House

KEY POINTS FROM THIS ARTICLE — As of this writing, just 379 of 435 House districts will have incumbents running in them this November. That’s the second-lowest total of the post-World War II era. — The 56 total open districts include 37 open Republican-held seats and 19 open Democratic seats. — The best pickup opportunities for both parties come in these open seats. — Since our last open seat update, the Democratic potential in these seats has grown: It’s possible the Democrats could get a third or more of the way toward flipping the House just through netting gains among the open seats. Updating the state of play in the House’s open seats In the roughly two and a half months since we last assessed an already-long list of House open seats this cycle — and even in the week since my colleague Geoffrey Skelley took a deep look at the pace of House retirements historically — the number of open House seats has continued to increase. At this point, only 379 of 435 House districts currently have an incumbent running for reelection. That is now the second-lowest total of the post-World War II era, trailing only 1992, when redistricting

KEY POINTS FROM THIS ARTICLE — The efficiency gap is a way to measure whether one party receives disproportionately more or fewer U.S. House seats compared to their share of the national House popular vote. — In the 1970s and 1980s, the Democrats generally won a greater share of seats than their total vote would have indicated. Since the mid-1990s, that Democratic advantage has morphed into a Republican advantage. The seats/votes relationship and the Efficiency Gap Redistricting for the U.S. House of Representatives is not a unified process, as is the case for most national legislatures, but rather the result of the cumulative actions in the states that have more than one representative. Nevertheless, it is useful to look at the entire House to see how the decisions in the states combine to form a fair or biased playing field for the parties. The traditional method for analyzing the partisan nature of the redistricting process is the seats/votes relationship, i.e. the link between the share of the national vote a party receives and the share of the seats it wins as a result (see here for a longer discussion). For this analysis, simple least squares regression is used to relate

KEY POINTS FROM THIS ARTICLE — By multiple measures — such as retirements, “pure” retirements, and open seats that must be defended — this cycle’s GOP has one of the highest levels of exposure in the U.S. House of any presidential party dating back to 1974. — Republicans already have more retirements than any presidential party in a midterm cycle from 1974 to 2018, and they are not far behind Democrats in 1978 in terms of the open seats they hold. Because seats lacking an incumbent are more difficult for the incumbent party to retain, this situation should deeply worry the GOP. — Earlier filing deadlines relative to past cycles mean that fewer GOP House members still have to decide if they are running for reelection relative to past presidential party House conferences. While additional retirements or surprise open seats might occur after filing deadlines have expired, the range of possible retirements might run from just a handful to the double digits. Midterm retirements and open seats in U.S. House elections from 1974 to 2018 In the aftermath of now-Rep. Conor Lamb’s (D) special election victory on March 13, a constant refrain has been the stated fear among Republicans that

KEY POINTS FROM THIS ARTICLE — An apparent Democratic takeover in a western Pennsylvania House district that President Trump won by 20 points is an embarrassing setback for Republicans. — The Republicans’ poor special election performances in general, combined with other factors such as the president’s low approval rating and a Democratic lead on House generic ballot polling, suggest the GOP House majority is in considerable danger. — Republicans remain favored in two pending special elections, AZ-8 and OH-12, but we are downgrading their chances in both. We also are moving three other races in Ohio from Safe Republican to Likely Republican. — That said, the AZ-8 and OH-12 specials have key differences from PA-18 that may make them easier for Republicans to defend. Table 1: Crystal Ball House ratings changes Conor Lamb’s (D, PA-18) apparent victory in a special House election in western Pennsylvania isn’t as much of a disaster for Republicans as Sen. Doug Jones’ (D-AL) win in a special election in Alabama was in December. But both results, combined with bigger-picture factors, suggest widespread Republican weakness as the midterm draws closer. Unlike Jones’ Senate seat, which Democrats will hold through at least 2020, Lamb’s newly-won House district

KEY POINTS FROM THIS ARTICLE — Based on the two-party vote, Trump won PA-18 by 20.3 points in 2016 while losing the national popular vote by 2.2 percentage points, meaning the district’s lean was 22.5 points to the right of the nation as a whole. Conor Lamb’s (D) apparent victory margin of 0.3 points in Tuesday’s special election equaled a swing of 22.8 points toward Democrats relative to the district’s 2016 lean. — The average swing for the GOP in U.S. House specials during President Donald Trump’s tenure is -13.7 points and the median swing is -18.4 points. These marks are worse than every modern president save Gerald Ford. — Lamb’s win on Tuesday was the 10th-largest swing against the presidential party in special elections in the past quarter century. Exploring special election swing, 1953 to 2018 Relative to the 2016 presidential election result there, the PA-18 special had a large swing in the Democratic direction. Looking at the two-party vote, Trump won the district by 20.3 points in 2016 while losing the national popular vote by 2.2 percentage points to Hillary Clinton, meaning the district’s lean was 22.5 points to the right of the nation as a whole. Conor

KEY POINTS FROM THIS ARTICLE — With less than a week to go, the PA-18 special election moves from Leans Republican to Toss-up. — In addition to that ratings change, we are making 25 other changes in the House, all in favor of Democrats. — No Democratic incumbent is now rated worse than Likely Democratic, a nod to the reality that in a Democratic-leaning environment it will be difficult for Republicans to dislodge many or perhaps even any Democratic incumbents, though there are a handful of Democratic open seats that are more viable Republican targets. — After these ratings changes, for the first time this cycle we have fewer than 218 seats (the number needed for a majority) at least leaning to the Republicans. — Making his debut in our competitive House ratings is the chamber’s most powerful member, Speaker Paul Ryan (R, WI-1). While his district is competitive but clearly Republican-leaning on paper, this shift mostly reflects uncertainty surrounding his future. Table 1: Crystal Ball House ratings changes Republicans sweat another red-seat special Amazingly enough, the special election in Pennsylvania’s 18th Congressional District now looks like a Toss-up. That’s one of 26 House ratings changes we’re making this week,

KEY POINTS FROM THIS ARTICLE — Assuming that a new court-drawn U.S. House map stands, Democrats should be able to cut into the Keystone State’s currently 13-5 Republican House majority. — The new map created one easy Democratic pickup, three Republican-held Toss-ups, and two other GOP seats that might be Democratic targets. — With an eye on possibly winning a House majority in November, Democrats likely needed to net three or more seats from Pennsylvania before the remap, and the new map should make that task easier. Breaking down the new Pennsylvania House map A few weeks ago, we plotted a potential seat-by-seat Democratic path to a narrow House majority. That included a Democratic target of netting three additional seats from Pennsylvania, and the state’s new House map drawn by the Democratic-majority state Supreme Court should make it easier to meet or even exceed that benchmark. The Keystone State stood out for having arguably the best Republican gerrymander in the country. The GOP-drawn map cemented a 13-5 Republican House majority, although that map hadn’t been tested in a pro-Democratic midterm environment, as 2018 should be to at least some degree. Democrats probably would have gained seats in Pennsylvania this November

KEY POINTS IN THIS ARTICLE: — In sketching out a potential path to a bare Democratic House majority of 218 seats out of 435, we found that in all likelihood the Democrats will need to win similar numbers of Republican-held seats won by Hillary Clinton as well as by Donald Trump in the last presidential election. Clinton-won districts are not enough on their own. — It is hard to construct a Democratic majority without the party netting several seats from California, and Democrats also likely need to win at least multiple seats apiece in New Jersey, New York, and Pennsylvania, where a new district map may be in the offing. — The growing number of Republican-held open seats may allow the Democrats to net a third or more of the seats they need to win the House from districts that don’t have an incumbent. But as we’ve previously said, the majority of Democratic gains will have to come from beating incumbents, unless considerably more Republican incumbents retire from vulnerable seats. Since we wrote an overview of open seats two weeks ago, two more swing district Republicans announced their retirements: Reps. Rodney Frelinghuysen (R, NJ-11) and Pat Meehan (R, PA-7). —

KEY POINTS IN THIS ARTICLE: — So far there are 46 House seats where an incumbent won’t be running for reelection in November. That is already above the postwar average, and more open seats are likely. — The current list of retirees includes 31 Republicans and 15 Democrats. Wave years sometimes but not always feature such a disparity between parties. — Of the 46, the Crystal Ball rates 18 as competitive. The seats likeliest to flip generally are held by Republicans. — In order to win the House, Democrats should net a half-dozen or more seats out of the total number of open seats. — But that’s only a portion of the 24 seats they need to win the House, so in all likelihood they still will need to defeat somewhere around 15-20 GOP House incumbents to win a majority. But that is not that high of a number historically. — Six ratings changes this week all benefit Democrats. They are explained below. Table 1: Crystal Ball House ratings changes A GROWING EXODUS FROM THE HOUSE Last week’s retirements by two prominent Southern California House Republicans, Reps. Darrell Issa (R, CA-49) and Ed Royce (R, CA-39), brought attention to a

There is a growing sense among political observers that the United States may be heading toward a wave election in 2018. Results of recent special elections, including Doug Jones’ (D) victory in the Alabama Senate race on Tuesday, along with Democratic victories in the New Jersey and Virginia gubernatorial elections and surprisingly large Democratic gains in the Virginia House of Delegates all point toward the likelihood of substantial Democratic gains in next year’s midterm elections, including a real possibility that Democrats could regain control of the U.S. House of Representatives. In addition, results of recent generic ballot polling generally show large Democratic leads. Despite these signs of an impending Democratic wave, however, many political experts believe that the way House district lines in many key states were drawn by Republicans prior to the 2012 election will make it difficult for Democrats to gain enough seats to take back control of the House. According to this argument, Republican gerrymandering was so effective that Democrats would need to win the national popular vote by a very large margin, perhaps eight points or more, in order to gain at least the 24 seats needed to take back the House. In order to test