In 2024, America swung to the right, powering Donald Trump back to the White House with the popular vote behind him and his Republican Party winning majorities in both the House and Senate. Just two years later, the country appears to be shifting in the opposite direction. Midterm elections are almost always a referendum on the party in power in Washington, and Democrats hope to capitalize on deep voter dissatisfaction with the president’s job performance and what they’ve framed as a crisis of affordability that Republicans have done little to abate.

The battle for the Senate, always more of an uphill climb for Democrats to win, appears close, with limited public polling showing tight contests in a number of key states. The House, however, appears to be Democrats’ to lose. Democrats could add anywhere from a handful of seats to several dozen to their count, according to an NBC News Decision Desk analysis of three different indicators of the national political environment. But it’s not impossible that Republicans could hang on — or at least, prevent the Democratic Party from running up the score — thanks to a friendlier map bolstered by Trump’s redistricting push.

Most Republican-held seats are in districts Trump won by double digits in 2024, meaning Democrats will have to reach further into states and districts Trump won to make big gains.

And while elections are more nationalized today than in the past, not every district will see its vote results shift perfectly in line with the national trend. The individual characteristics of a district, as well as what voters there care about, play an important role in determining a winner. The candidates themselves matter, too, and incumbency can still be a powerful advantage for those seeking re-election. Even so, looking ahead to how House control could play out on election night requires making an assumption about the size of the national partisan shift toward Democrats, and away from the baseline set by 2024.

For our analysis, we examine three ways of estimating that shift: recent polling data, past vote patterns and special election results.

If the polls are right Districts to .S. House be controlled by the Democrats, and 43% prefer the Republicans to be in control. This 9-point gap also matches the preferences of all registered voters in the most recent NBC News Decision Desk poll. To turn this 9-point margin into a shift, we compare it to the national popular vote in 2024.

Trump won the popular vote by 1.5 percentage points, meaning that a 9-point preference for the Democrats in 2026 translates to a 10.5-point shift from the 2024 results. There are 238 House districts that Trump lost or won by less than 10.5 points, meaning that a shift this size could result in the Democrats winning 238 seats, a slightly larger congressional majority than they did in the 2018 midterms at 235.

Under this scenario, we would expect to see extremely close races in some of those Democratic-held districts that Republicans redrew since Trump’s re-election in an effort to create safe Republican seats. One example is Ohio’s 9th District, where Democrat Marcy Kaptur, the longest-serving woman in congressional history, is seeking re-election. Republicans have tried unsuccessfully to oust Kaptur for years, and her district was redrawn last year to be out of reach for even someone with her political survival skills. Trump would have won it in 2024 by 10.6 points.

A national shift of 10.5 would give Kaptur at least a fighting chance to thwart her Republican opponents once again. Florida’s 14th District is another. Republicans redrew its lines so that Trump would have won it in 2024 by 10.5 points. If the national shift is 10.5 points, Rep. Kathy Castor, the Democratic incumbent, will have a chance to hold the seat.

Finally, look at Rep. Henry Cuellar’s heavily Hispanic district along the U.S.-Mexico border, Texas’s 28th. Republicans redrew this formerly 7-point Trump district into a 10.4-point one in the hope of finally dethroning Cuellar, who has survived despite South Texas moving to the right, and despite being indicted on bribery and money laundering charges. (He was later pardoned by Trump.) Even though Republicans are excited about their candidate, Tano Tijerina, and have spent big to keep the seat competitive, the Decision Desk rates the race as lean Democratic.

If the polls are underestimating Republicans Districts to . If that’s true this year, the battle for the House looks more like a coin flip. Voter demographics in the most recent midterms, 2022, with then-President Joe Biden in the White House, favored Republicans, were older and whiter. If we take the demographic profiles of the most recent Decision Desk poll respondents and compare them with the typical composition of those 2022 voters, as we did for a recent polling analysis, that 9-point advantage for Democrats among registered voters shrinks to just a 4-point lead over the Republicans.

Comparing this finding to the 2024 results suggests that, under this scenario, the national shift would be about 5.5 points toward the Democrats. A shift of this size still gives Democrats a razor-thin edge — 220 seats for the Democrats to the Republicans’ 215. A slim majority like this would match the pattern of the past three general elections, where neither party has come out of the election with a majority of more than nine seats. The GOP’s path to maintaining its majority would require a slightly narrower national shift toward the Democrats — about 4.5 points — or a few Republican candidates outrunning the national political headwinds by just enough to win some close races.

In these instances, party control of Congress would come down to districts like Pennsylvania’s 10th District. Represented by Republican Scott Perry, it’s been a target of the Democratic Party for the past few elections, without success.

In 2024, Trump won the district by 5.3 points, while Perry carried it by only 1.3 points. For the Republicans to hold the House, they would need Perry to outperform that national shift. Virginia’s 1st District could also be competitive in this scenario. Republican Rob Wittman won this seat by 12.8 points in 2024, but Trump carried it by just 4.9 points. (Had the Virginia Supreme Court not struck down state Democrats’ attempt to redraw the congressional map earlier this year, this district would have voted for then-Vice President Kamala Harris by 17 points.)

The party that ends up controlling Congress in 2027 could come down to whether Wittman can beat the national trend like he did two years ago. And if Republicans can manage to hold both of these districts and others like them, the party would keep the House by a slim margin. If the special elections in 2025 and 2026 are a bellwether Districts to 026, ever since Trump took office.

These races include the 2025 governor’s elections in New Jersey and Virginia, other high-profile statewide elections and several special elections for the U.S. House. Although Trump lost Virginia and New Jersey, the other recent elections have tended to occur in places that supported Trump in 2024. Averaging across all of these states and districts, Trump won them by an average of about 3.5 percentage points in 2024. In the 2025 and 2026 elections, however, those states and districts supported the Democratic candidate by an average of about 11 points.

This amounts to a shift of 14.5 points in the Democrats’ favor. If the Democrats are able to shift the vote in every district by such a historically massive margin in 2026, they could win as many as 263 seats to the Republicans’ 172. That would be the largest majority that either party has held in the U.S. House since the 1990 midterm elections. Such a shift could put into play districts like Florida’s 27th District, represented by GOP Rep. María Elvira Salazar.

Republicans in Florida left this district nearly unchanged when they redrew the state’s congressional map, believing that a district that Trump won by 14.6 points would be out of reach for the Democrats.

But it appears the race in this heavily Hispanic district is tightening, as polls show Latino voters nationwide turning against Trump and Republicans, with economic concerns weighing heavily on their minds. These voters were critical to Trump’s winning coalition in 2024, and indications that they are moving back toward Democrats are helping drive the party’s competitiveness in Republican-leaning, heavily-Hispanic districts in states like Texas, too.

Salazar outran Trump’s win margin by nearly 6 percentage points in 2024, and her survival in the 2026 election may require a similarly strong overperformance. A 14.5-point national swing toward Democrats could also make North Carolina’s 14th District competitive. Republican Rep. Tim Moore’s district is one that North Carolina Republicans did not bother changing when redrawing their maps last year.

Trump won the district by 15.1 points, and Moore himself won it in 2024 by 16.1 points. Another district to watch is Kentucky’s 6th District. This open Lexington-based seat has been held by Republican Andy Barr since 2013, and was carried by Trump in 2024 by 15.0 points. Barr is running for the U.S. Senate this year.

Republican and Democratic-aligned groups are spending heavily here, reflecting the importance of the race, as Republican Ralph Alvarado faces off against Democrat Zach Dembo. The NBC News Decision Desk rates this race as lean Republican. In 2024, this district reported almost 90% of its votes by 8:40 p.m. ET. If Democrats are on track for a massive national shift, this district may provide one of the best pieces of early evidence.

National trends don’t mean every district shifts the same amount To be sure, all of these scenarios assume that the partisan shift in 2026 will be the same in every district.

This may be true on average, but some districts will have a larger shift than the national average and others will have a smaller one. Demographics of a specific district may play a role in the size of the shift. For example, if Hispanic voters shift more dramatically toward the Democratic Party than non-Hispanic voters, then districts with higher concentrations of Hispanic voters will vote more favorably for the Democrats than the underlying partisanship of the district would predict. Incumbency can also play a large role in causing a district to shift more or less than the national average.

In 2024, the incumbent members of Congress outperformed their party’s presidential candidate by an average of 2.5 percentage points. This year, there are slightly more Democratic incumbents seeking re-election than Republican ones. This means that the Democratic Party as a whole stands to gain more from the benefits of incumbency compared with the Republican Party. On the other hand, there are more Republican incumbents who represent districts with an evenly divided underlying partisanship. For example, an “incumbency bump” matters a lot more to a Republican in a district Trump won by 5 points than to a Democrat in a district Harris won by 25 points.

Finally, redistricting has also played a key role in this year’s midterms. By redrawing districts in several states, Republicans stand to win as many as 10 more seats than if the map remained unchanged after 2024. Redistricting impacts the role of incumbency, too. When the lines for a district are redrawn, incumbents are now fighting for the votes of people whom they’ve never represented, and who may be less familiar with their record.

This tends to diminish the size of the incumbency advantage. Republican incumbents in Texas and other red states and Democratic incumbents in California must lean heavily on the “D” or “R” next to their name when they try to win the support of their new potential constituents.