Now that congressional maps are likely finalized for the 2024 elections, we know that the House battlefield will be even more tilted toward Republicans this year than it was in 2022. This state of affairs is a direct result of Republicans in Congress and the Supreme Court’s conservative supermajority repeatedly blocking efforts to end gerrymandering nationwide.
We can demonstrate how this distortion works using Daily Kos Elections’ calculations of the 2020 presidential election results for every district that will be used in 2024. These results are visualized in the map at the top of this story (click here for a larger image), as well as in this cartogram that shows every district equally sized.
One way to measure a map’s bias toward either party is to rank every district from bluest to reddest. There are many ways to assess a district’s partisanship, but presidential election results give us a consistent baseline that also correlates strongly with downballot performance. That is to say, if a district voted for Joe Biden, the chance is overwhelming that it also supported a Democrat for the House, and vice-versa if it voted for Donald Trump.
To perform this ranking, we sort every district from Biden’s widest margin of victory to Trump’s largest win. This way, we can look at the district in the very middle—the median—and compare it to the national popular vote for president. This allows us to gauge how much voter support each party would need to win a bare majority of 218 districts.
Biden would have won 224 districts on the 2024 map, compared with 211 for Trump, but the president’s margin in the median district, Virginia’s 2nd, would have been just 1.9 points. Since Biden won the national popular vote by a wider margin of 4.5 points, the median district would have been (after rounding) 2.5 points to the right of the nation as a whole.
Put differently, if every district were to shift toward Trump by the same margin, he could have lost the national popular vote by 2.5 points yet still carried a majority of districts in the House. In a nation as closely divided as ours has been in recent years, that advantage could make the difference in terms of which party wins the House in a tight election.
And not only does the median district favor Republicans, it’s gotten more favorable to them due to a further round of redistricting in five states that followed the 2022 midterms.
In 2022, the median district was Michigan’s 8th, which Biden would have carried by 2 points. Since the new 2024 median, Virginia’s 2nd, backed Biden by just 1.9 points, that means the median has now moved to the right. In addition, Biden would have won a 226-209 majority of districts on the 2022 map, meaning the 2024 map has two fewer Biden districts overall.
Those shifts might seem small, but with control of the House balanced on a knife’s edge, they could loom very large. And the end result dashed widespread expectations earlier this cycle that litigation in several states could result in a fairer map overall.
Despite the tilted playing field, Republican candidates for the House collectively won a similar share of the nationwide vote as they did seats in the House—roughly 51%. But it’s very possible that their share of seats will outstrip their proportion of the vote this year because turnout dynamics will likely be different in a presidential election.
Another way to assess the GOP’s advantage is by looking at how many districts nationwide were drawn with the intent to favor Republicans or Democrats, or were intended to favor neither party. We’ve illustrated this on the cartogram below, in which states are sized according to their number of districts (click here for a larger image).
Forty-two percent of districts were drawn to favor Republicans while just 14% were drawn to favor Democrats. The rest were drawn without discernible partisan intent, mostly by courts and commissions. These proportions were virtually unchanged compared to the 2022 map.
Under the Constitution, every state was required to redraw its congressional map following the most recent census, but five of them did so a second time following the midterms. Each of these cases involved the courts in some capacity.
In Alabama and Louisiana, successful lawsuits under the Voting Rights Act compelled the creation of two new districts where Black voters should be able to elect their preferred candidates. As a result, one Republican-held seat in each state will almost certainly flip toward Democrats.
In Georgia, though, a similar lawsuit saw the state’s map overturned only for Republicans to pass a new map that maintained the partisan status quo, once again locking in a wide advantage for the GOP.
Meanwhile, North Carolina Republicans enacted one of the most extreme maps in the country after winning back control of the state Supreme Court, which immediately overturned its own previous ruling that banned partisan gerrymandering. The GOP’s new map replaces a court-drawn plan and shifts four Democratic-held districts much further to the right, making three of them unwinnable for their current incumbents and endangering the fourth.
Many observers had expected New York Democrats to counteract North Carolina’s new map by replacing their state’s own court-drawn map with a new gerrymander. But Democrats unexpectedly made only minor changes and even turned one Biden district into a Trump district to boost a neighboring incumbent.
These adjustments were so modest that Ed Cox, who chairs the state Republican Party, said the GOP had “no need” to sue because the new “lines are not materially different from” the court-drawn map used in 2022, which he described as “fair.”
In the final analysis, Republicans are all but guaranteed to net an additional seat, since the three safely red districts they gerrymandered in North Carolina outweigh the two new VRA districts in Alabama and Louisiana. So while Democrats, on paper, need to net four seats to take back the House, in practice, they’ll need five.
Democrats still have a strong chance to do just that, particularly given the House GOP’s escalating disarray. But widespread Republican gerrymandering still puts Democrats at a distinct disadvantage—a disadvantage that’s only grown worse over the last two years.