Like the presidential contest, many congressional races teeter on a knife’s edge this year. Recent cycles have seen a collapse in ticket-splitting, so the fates of down-ballot races are increasingly tied to the top of the ticket. Across the 2016 and 2020 presidential elections, only a single state split its ticket in the presidential and Senate races (Susan Collins, the ultimate survivor, won reelection in Maine in 2020, while Donald Trump lost the state). In today’s hyper-polarized environment, the presidential race is the sun around which the other races orbit. The clash between Trump’s Grand New Bargain and Kamala Harris’s Belmont+ coalitions could shape the battle for Congress, too.
As of this writing, Republicans have a relatively clear path to 51 seats in the Senate, but the road beyond that is uphill. Right now, the GOP has 49 seats in the chamber, and current Republican governor Jim Justice seems to have a lock on the West Virginia seat held by the retiring Democrat-turned-independent Joe Manchin. While Republican presidential candidates have racked up big wins in Montana, Democrat Jon Tester has a knack for winning close: in his three Senate races, Tester’s victory margin has been under five points. Tester is almost certain to run ahead of Kamala Harris—the question is by how much. Essentially every public poll released this fall has given the Republican nominee, Tim Sheehy, a lead over Tester, causing many observers to think that the farmer from Big Sandy’s luck is about to run out. That’s 51 for the GOP.
After that, it gets harder for Republicans. Many analysts rate Senate races in Michigan, Pennsylvania, Ohio, and Wisconsin as toss-ups, and Nevada could also be competitive. Though ranked as battlegrounds in recent cycles, these states have often delivered heartbreak for Republicans, with Democrats consistently holding almost all of them since 2007. (The one exception is the Nevada seat, which was Republican until 2018.)
Ohio is perhaps the most likely seat to shift into the Republican column. Trump won the Buckeye State by healthy margins in both 2016 and 2020, and Ohio senator J. D. Vance is on the ticket with him. Like Tester, incumbent Democrat Sherrod Brown was elected to the Senate in the anti-Republican wave of 2006, and Brown’s populist flair and ability to reach out to blue-collar voters have contributed to his political longevity. But Brown’s Republican challenger, Bernie Moreno, has assailed him on the border and inflation, tying the incumbent to the unpopular records of Harris and Joe Biden. Brown has reportedly said that he thinks he can hold on if Trump wins Ohio by less than eight points. That seems a reasonable benchmark; at a certain threshold, the top of the ticket becomes too hard to resist. Heightening this political drama, many polls give Trump a lead in Ohio of about eight points.
Perhaps even more than Ohio, the “blue wall” states of Pennsylvania, Wisconsin, and Michigan are tied to the presidential contest. In Pennsylvania and Wisconsin, Democratic incumbents are facing well-funded challenges from their Republican rivals, and polls show the states close in both the presidential and Senate races. Michigan is an open seat, and Republican nominee Mike Rogers has run a capable campaign. However, Democratic nominee Elissa Slotkin is a talented politician and holds a slight lead in many polls. It’s been 30 years since Michigan elected a Republican to the Senate. A strong Trump performance in these states could put Republicans over the top.
Democrats’ pick-up opportunities seem to be fewer. Originally, they hoped to make a play for Florida’s Senate seat, but the Sunshine State has increasingly trended Republican, and Trump seems to have a significant polling lead there. So it’s hard to see how the Democratic challenger could topple incumbent senator Rick Scott. Likewise, some polls have shown that the Texas Senate race could be close, but Trump seems favored to win Texas. The Lone Star State rarely splits its presidential and Senate votes, and no Democrat has won statewide office in many years. Two-term incumbent Ted Cruz thus seems well-positioned to win reelection. Conversely, a Cruz loss on election night could be a dire sign for Republicans nationally; it would likely mean that suburban voters were fleeing from the GOP across the board.
Nebraska is a sleeper race. Incumbent Republican Senator Deb Fischer is facing an unexpectedly strong challenge from independent candidate Dan Osborn. To some, this contest has echoes of the 2014 Senate race in neighboring Kansas, where incumbent Republican Pat Roberts seemed down in polls against independent Greg Orman but wound up winning by more than ten points. Nebraska is expected to go overwhelmingly for Trump next week, and, while Osborn has led with blue-collar branding, he is also fundraising through the Democratic-aligned platform ActBlue. If Fischer can tie him to the Democratic Party nationally, she could stave off his challenge.
Perhaps fittingly for the branch of the federal government meant to be closest to the people, the House of Representatives represents how nail-bitingly close recent elections have been. Democrats narrowly won a majority of 222 seats in the 2020 presidential election. Republican also garnered 222 seats during the 2022 midterms, and the topline number might understate how tight those races were. While Republicans won the “popular vote” for the House by about three points in 2022, their single-digit majority relied on hair’s-breadth margins in a handful of swing seats. One analysis from late November 2022 found that a shift of only a few thousand votes across five seats would have kept Democrats in control of the House. Thus, even though Republican House candidates got about 3 million more votes than Democratic candidates, the actual electoral tipping point was a tiny fraction of that.
All this suggests that the House map does not favor Republicans to the extent that it did in the 2010s. Theoretically, Republicans could win the “popular vote” at both the presidential and House levels and still lose control of the House. Generic-ballot polls suggest that the House is currently a coin flip, a diagnosis only reinforced by analyses of particular battlegrounds.
The Cook Political Report rates 25 seats as “tossups.” Almost half the seats in this category come from only three states: California, New York, and Pennsylvania. These mostly suburban districts were fiercely contested last cycle and remain on the frontlines today. It’s thus no surprise that Trump has been campaigning in both California and New York. Even if these states are not up for grabs at the presidential level, they have majority-making seats in the House.
Based on the 2022 midterms, Kamala Harris’s Belmont+ coalition could be optimally configured to make inroads in the suburbs. In many of these suburban districts in Arizona, New York, and elsewhere, Democrats are relying on abortion politics to take down Republican incumbents.
For their part, Republicans may hope that high turnout among working-class voters will pad their numbers in the House. One of the most rural districts in the nation, Maine’s 2nd congressional district, has voted for Trump twice already. Democratic incumbent Jared Golden has survived multiple close calls, and he only won the seat in 2018 because of Maine’s ranked-choice voting law (which kicks in when no candidate reaches 50 percent). This year, Golden is up against former NASCAR driver Austin Theriault, and polls suggest the race could be close yet again. Another blue-collar bellwether could be Ohio’s 9th congressional district, surrounding Toledo. While this district only narrowly backed Trump in 2020, incumbent Democrat Marcy Kaptur has been in Congress for more than 40 years. She easily dispatched a controversy-laden Republican challenger in 2022, but many analysts still consider this a top battleground. A strong Republican performance in this district could be a sign that Trump’s Grand New Bargain coalition is gaining ground.
This year’s congressional races have longer-term political stakes. Since Bill Clinton’s 1992 presidential win, every non-incumbent has entered the White House with a political trifecta. That could change this year. It’s possible that the House could break a different way than the presidential race—which would dramatically complicate either Trump’s or Harris’s attempt to enact a political agenda. If Republicans can muster at least 51 seats in the Senate, they will have considerable leverage over Harris’s Cabinet choices. And the results of this year’s Senate races will have major consequences for the 2026 contests. Especially if Trump wins the White House, Republicans could face a brutal map in 2026; picking up a few extra seats in 2024 could provide them with a crucial safety margin.
Zooming out to the national political picture, this congressional battle reveals a structural asymmetry between the Republican and Democratic coalitions. The Democrats are more disciplined and capable of achieving structural changes with the narrowest of majorities. A Democratic trifecta with a narrow House majority and a 50-50 Senate could very well allow the party to nuke the Senate filibuster and push through a sweeping package of abortion legislation, forced retirements on the courts, and even adding new states to the Union. But the Democrats’ progressive discipline has also narrowed their appeal nationally. Relative Senate moderates like Joe Manchin and Arizona’s Kyrsten Sinema left the party, and a Democratic incumbent like Jon Tester is vulnerable precisely because he has not shown much independence from Democratic elites. Over the past decade, the party has spurned the political diversity that built the filibuster-proof Democratic majorities of the early Barack Obama years.
As proven by the past two tumultuous years in the House, Republicans remain more fractious. The party seems unlikely to muscle through radical legislative changes with tiny majorities. The GOP’s incoming class is also likely to make the Republican Senate caucus even more populist; Indiana representative Jim Banks has been one of the leading voices for a populist-conservative fusion in the House, and he is widely expected to win Indiana’s open Senate seat next week. However, this very heterogeneity could also help Republicans lift their political ceiling in Congress. A vast and sprawling country like the United States needs a similarly expansive governing coalition, and the party that can accommodate that range could reap rewards in the years ahead.
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