Retirements and reversals in gerrymandering give Democrats a clearer path to a majority.
The Democratic advantage on the generic congressional ballot has slipped over the last few weeks. But Republicans have gradually lost advantages of their own.
Slowly but surely, the considerable structural advantages — like incumbency, geography and gerrymandering — that give the Republicans a chance to survive a so-called wave election are fading, giving Democrats a clearer path to a House majority in November.
The Republicans still retain formidable advantages, enough to win the House while losing the national popular vote by a wide margin. But their edge has shrunk considerably over the last few months, and even more over the last few years.
One way to think about it is how well Democrats would need to do on the generic ballot — a poll question that asks voters whether they’ll vote for Democrats or Republicans for Congress — to win the House. A bigger Republican structural advantage means the G.O.P. can withstand a larger Democratic advantage on the generic ballot.
By this measure, the Republican advantage has probably dropped by about two percentage points since 2014, when Republicans won the party’s largest House majority since 1929.
Since then, four court rulings have softened or even torn up Republican gerrymanders in four big states: Florida, North Carolina, Virginia and most recently Pennsylvania, where the state Supreme Court struck down the congressional map last month.
The decisions in Florida, North Carolina and Virginia have already cost the Republicans a net of three House seats while generally eroding their position elsewhere in those states, giving Democrats better opportunities in 2018.
It’s too early to have a good idea of how much Republicans might lose in Pennsylvania, but it is reasonable to expect that the new map will cost the party at least one seat and erode its position in several others.
Gerrymandering is not the only reason Democrats are at a disadvantage. Republicans also have the advantage of incumbency, which, on average, allows members to run about seven percentage points ahead of the national party.
But Republicans have gradually been losing the advantages of incumbency as well, most obviously because of 34 recent retirements in Republican-held congressional districts.
Over all, the number of G.O.P. retirements in plausibly competitive districts isn’t extraordinarily high. But some of the Republican retirements have been especially damaging: longtime incumbents who have a tradition of running far ahead of the national party and dissuading strong challengers, like New Jersey’s Frank LoBiondo or Pennsylvania’s Charlie Dent. Their retirements could easily be the difference between a non-competitive race and a Democratic victory.
The Republican incumbency advantage has diminished in another way: Democratic recruitment and fund-raising. A strong Democratic recruit — like a military veteran or an elected official — can cut into that advantage, especially with strong fund-raising numbers.
As measured by biographical indicators like military experience or past elected officials, Democratic recruitment is only somewhat above average at this stage. But much like the Republican retirements, the best Democratic recruits have often been extremely valuable.
Often, Democrats have succeeded in finding their very best candidates in white working-class districts where President Trump fared well in 2016. His strength threatened to move many traditional battlegrounds into the Republican column. The Democratic path to a House majority arguably looked even more difficult after the 2016 presidential than it did before — even though Democrats picked up seven seats in that election, since so many traditional battleground districts swung hard for Mr. Trump.
But strong Democratic recruiting in Trump Country has kept many traditional battlegrounds on the list, like Illinois’ 12th or Kentucky’s Sixth. The Democrats might have an easier time finding qualified and experienced recruits in white working-class districts in part because Democrats have a track record of winning there, and therefore a deeper bench, even if Mr. Trump won a particular district.
In contrast, the Democrats don’t have much of a bench at all in many of the well-educated but traditionally Republican districts where Mr. Trump struggled the most. Here it’s the Democratic fund-raising that is most impressive. Last quarter, 134 Democrats in 83 districts raised at least $100,000 in individual contributions. Those successes have been disproportionately concentrated in well-educated areas.
It’s the working-class districts where Democrats are likeliest to have true recruiting holes, like New York’s 24th or California’s 21st. That might seem somewhat odd because Democrats have had so much success luring top-tier candidates in working-class districts.
In fact, Democrats do have well-qualified, potential candidates in these districts, like the state assemblyman Rudy Salas or the former Syracuse mayor Stephanie Miner, but many aren’t running. (Mr. Salas hasn’t entered the race in California’s 21, and Ms. Miner has decided not to run in New York’s 24th.) It seems these areas may not be stocked with ambitious, well-to-do and well-connected liberals eager to run when an elected official doesn’t step forward.
Even so, Democrats still seem poised to have viable if imperfect candidates in a large number of battleground districts. Upshot estimates indicate that Democrats would need to win the popular vote by 7.4 points — albeit with a healthy margin of error of plus or minus more than four points — to take the House. Today, most estimates put the generic congressional ballot very near that number. So far from the election, the fight for control remains a tossup.