It was expected that Election Day this year would end with Republicans in clear control of the House and well positioned for a majority in the Senate. Both historical patterns and national polling suggested that the GOP would easily pick up the five seats necessary to seize a House majority; the question was how much further the party would roam.
Instead, Election Day ended with uncertainty. Republicans underperformed relative to expectations in a wide range of contests, and control of both chambers of Congress remained up in the air. If the party does manage to secure a majority in the House — a question still unsettled as of this writing — it may be thanks not to those historical patterns or that polling but to something much more mechanical.
A Republican majority may be thanks almost entirely to the party’s success in redrawing district boundaries after the 2020 census.
To win a majority in the House, a party needs to hold 218 of the chamber’s 435 seats. If current results hold, the Republican Party will probably hit that mark. Analysis from The Washington Post’s election model combined with races already called by the Associated Press suggests that the Republican count will be about 225 — eight seats into the majority. Certainly a narrow enough margin that House Minority Leader Kevin McCarthy (R-Calif.), should he be elected speaker, would have his hands full keeping his caucus pointed in the same direction.
It’s not hard to identify where redistricting gave Republicans eight seats they might not otherwise have had.
We can start with Florida, the brightest spot on the Republican map Tuesday night thanks to Gov. Ron DeSantis’s overwhelming reelection victory. It was also one of the brightest spots in the party’s redistricting effort.
As was the case in most states, the drawing of new congressional boundaries that followed the release of demographic data from the 2020 Census yielded a number of competing delineations. Florida not only had to draw a new map but also gained a new district to be carved out of existing areas, making the effort trickier than normal.
The state legislature approved a new congressional map, sending it to DeSantis’s desk for approval. But DeSantis rejected it, calling a special session of the legislature to resolve the question. At that session, DeSantis advocated maps created by his office (with the assistance of external conservative attorneys). The map DeSantis presented was much more aggressive in creating districts friendly to Republican candidates; when the legislature passed it, he signed it into law.
What resulted was a map in which the state gave up three contested seats relative to its previous map and gained four Republican-leaning ones. Democrats and advocates of Black voters — whose votes had been diluted by being split between different districts — sued. But the Florida Supreme Court let the new map stand.
Before redistricting, Republicans had a five-seat advantage. The districts that resulted from DeSantis’s maps gave the GOP a 12-seat advantage, one that held up in the midterm elections. While there is no guarantee that the old lines would have resulted in the same partisan divide in this cycle as there was in 2020 (those three contested seats, for example, might have gone Republican anyway), the shift of even four seats to the GOP would account for half of the GOP’s expected majority.
The fight over redrawn congressional boundaries landed in court in several other states. Four of those states — Alabama, Georgia, Louisiana and Ohio — were allowed to use contested maps for this election cycle despite either significant legal challenges or outright recognition that the maps violated legal requirements. As Cook Political Report’s Dave Wasserman said to the New York Times in August, those legal decisions alone might have been enough to secure an extra five to seven Republican seats.
Consider what happened in Louisiana. A U.S. district court judge rejected the state’s proposed maps in June, specifically pointing to the state’s history of disenfranchising Black voters. (That some of these challenges came in the first redistricting after the Supreme Court weakened the Voting Rights Act is not a coincidence.) But the U.S. Supreme Court blocked the order to draw new maps, echoing a February decision centered on Alabama.
The Louisiana map was unsubtle in scooping as many Black voters as possible into one heavily Democratic district. The result is a map in which 1 in 3 Black Louisianans will live in a district probably held by a Democrat, though 3 in 4 Black residents of the state are Democrats. Only 1 in 40 Black residents are Republicans, but two-thirds of them will live in districts that will probably be represented by a Republican in the House.
Here, the effect of the court decisions wasn’t to shift seats to the GOP. Instead, allowing Alabama and Louisiana to keep their redrawn maps had the effect of preventing the creation of districts that might have been more likely to elect Democrats. In Louisiana, for example, the original court order was to create a second district in which Black voters had a heavy presence, increasing the odds that two of the state’s six districts might have been blue. That would be a two-seat GOP advantage, instead of the four-seat advantage the party might expect under the maps that were allowed to move forward for this year’s ballot.
Then there’s New York. As in Florida, the process was tumultuous: An independent commission was unable to reach a consensus on maps, so, after the Democratic legislature rejected the two proposals, politicians set about creating their own version. It was signed into law by Gov. Kathy Hochul (D) — and then quickly challenged.
As in Florida, it was up to the state’s highest court to determine if the legislature-passed maps — heavily favoring the incumbent party, also as in Florida — would be allowed to stand. But in New York, the judge threw them out.
Had those initial maps stood, FiveThirtyEight’s analysis suggests that Democrats would have gained three seats as the GOP lost three. Instead, the new map was a wash, with each party losing a safe seat and a new competitive seat being created. More alarmingly for Democrats, the median seat in the state shifted to the right by four points, in part a reflection of New York’s urban-rural divide.
Again, it’s impossible to know what would have happened under the initially proposed map. But between the AP calls and The Post’s election model, it’s likely that Republicans will win 10 of the state’s 26 seats, compared with the six seats seen as competitive or Republican-leaning under the map rejected by the court. That’s another four seats the GOP might have gained as a result of the redistricting process — or, at least, that it didn’t lose.
House races are 435 individual fights between 870 or so potential candidates. National trends affect how each party fares, but the parties’ fates often come down to the state of play in a particular place. Redistricting affects who chooses to run in those places and how likely a victory will actually be.
This year, the newly drawn maps — and the ones that were rejected — might have been enough by themselves to ensure a Republican House majority.