10 Senate Seats Most Likely to Flip in 2024

Following their unexpected gain of a Senate seat in 2022, Democrats hold a 51-49 majority in the United States Senate. While 2022 managed to avert expectations, 2024 is set to be a brutal year for Democrats. With only a handful of red states to target, Democrats will be playing almost entirely on defense.

Most importantly, three Senate Democrats represent states Donald Trump won by large margins in 2020. In other words: the path to a majority runs through red states. Here are the 10 Senate seats we see as most likely to flip – along with one honorable mention.

Honorable mention – Florida (Rick Scott, Republican)

Fresh off a 2022 midterm that saw Governor Ron DeSantis sweep to a landslide re-election by a margin of 19%, Florida Republicans appear to be in a better position than ever. Incumbent Republican Rick Scott, then, should be favored in 2024. However, there’s reason to believe his chances at victory aren’t absolute.

Scott has achieved national notoriety for an unpopular legislative agenda, and his previous three statewide wins were all by impossibly small margins (1.2%, 1.0%, and 0.12%). Florida Democrats lack any real bench, and it’s likely that the state will be carried by the Republican presidential nominee. However, it’s quite possible Scott underperforms to some degree. We have this race at Likely Republican.

10: Virginia (Tim Kaine, Democrat)

Virginia isn’t truly a swing state at the federal level; Republicans haven’t won a federal race here since 2004. However, we do think this race is worth paying attention to. Virginia Republicans have proven to be surprisingly competent as of late; they won every statewide race in 2021, along with a majority in the House of Delegates.

In 2022, Democrats carried the popular vote in the House by only 3.4%, an underperformance driven in large part by Republican Hung Cao holding Jennifer Wexton to a 6.6% win in a Biden+18 seat. Now, Cao is strongly considering a run for Senate. Incumbent Democrat Tim Kaine is popular, but we feel this race is one that’s worth keeping an eye on. This race is currently rated as Likely Democratic.

9: Texas (Ted Cruz, Republican)

Incumbent Republican Ted Cruz survived a scare in 2018 when he won re-election by a narrow 2.6% margin. However, this result was in the midst of the biggest blue wave since 1975. Democrats haven’t won a single statewide race in Texas since 1994, and they lack a real bench. The Texas Democratic Party has such a poor track record that it’s hard to give them the benefit of the doubt.

On the other hand, Trump only carried Texas by a 5.6% margin, and the state should be somewhat competitive again in 2024. We think Cruz is the favorite here – especially with the nonexistent Democratic field. But if the state pulls closer than it was in 2024, an underperformance from Cruz could spell trouble. We have this race at Likely Republican.

8: Pennsylvania (Bob Casey, Democrat)

Senator Bob Casey has long been one of the more popular incumbents in Pennsylvania, and we think he’s the favorite for a fourth term. While Pennsylvania is one of the premier swing states in the country, and we don’t expect that to change in 2024, Casey is an entrenched incumbent. More importantly, Pennsylvania Republicans are in disarray after a wildly disappointing 2022 midterm that saw them lose a Senate seat and the state house.

There are a handful of credible candidates Republicans could put forward, including 2022 primary runner-up David McCormick. There’s also no shortage of subpar ones priming to run, too. Casey is the favorite here – we rate this as Likely Democratic.

7: Michigan (Open, Democrat)

Normally, the announcement of a retiring Senator from a pivotal swing state would push that state to the forefront. But that’s not the case in Michigan, a state we have as Leans Democratic. Incumbent Debbie Stabenow won re-election by fairly wide margins three times. Her retirement, in theory, creates a greater opening for Republicans.

However, a decimated Republican bench has left them with limited options. Rep. John James, who won a tossup house district that went for Gretchen Whitmer by 10 points, has already lost two Senate races. Rep. Bill Huizenga might be the best bet here, but the Republican field is certain to be wide. Democrats, on the other hand, appear to be waiting for Rep. Elissa Slotkin to announce. Slotkin, a three-term House member, would be a formidable candidate; she’s won all three terms in competitive or Republican-leaning districts.

6: Nevada (Jacky Rosen, Democrat)

Once seen as a state demographically in line with the developing Republican coalition, Nevada has instead established itself as the Democratic equivalent of North Carolina. While Republicans can and do come close, federal wins have tended to escape their grasp. Republicans have only won one federal race here since 2006 – a Senate race in 2012, with only 45.9% of the vote. Even more interestingly, polls in Nevada have tended to underestimate Democratic support.

First-term incumbent Jacky Rosen was elected in 2018’s blue wave, securing a 5% win over then-incumbent Senator Dean Heller. Like her colleague Catherine Cortez Masto, she’s generally adopted a low profile as a Senator. The potential Republican field is pretty sparse as of now. Perhaps the most noteworthy potential candidate is Sam Brown, a Purple Heart recipient and the runner-up in the 2022 primary. We have this race as Leans Democratic.

5: Wisconsin (Tammy Baldwin, Democrat)

Wisconsin has rapidly become perhaps the nation’s most pivotal swing state, and this Senate contest is expected to be a key one to watch. Two-term incumbent Tammy Baldwin easily won re-election amidst 2018’s blue wave, and has fairly average approval ratings. However, Republicans have a fairly solid bench to choose from.

Their most compelling option, Rep. Mike Gallagher, is extremely popular in his Green Bay-based seat. For now, though, have this race as Leans Democratic. Baldwin shouldn’t be underestimated, and it’s possible Republicans repeat their 2022 gubernatorial woes by nominating a poor candidate.

4: Montana (Jon Tester, Democrat)

While Montana is a firmly Republican state at the federal level, and has gradually become one at the state level, incumbent Senator Jon Tester is perhaps the best-positioned of the three Trump-state Democrats. A recent GOP-aligned poll showed Tester with a +16 approval rating, but that’s not the only reason we think he’s in a reasonably good spot.

Both of Tester’s likeliest rivals – Reps. Ryan Zinke and Matt Rosendale – are extremely flawed candidates. Zinke resigned in scandal from a Cabinet position, while the Maryland-born Rosendale lost to Tester in 2018. A Tester victory would still be difficult – this is a state Trump carried by 16% in 2020, after all. But unless Republicans can really up the game on candidate quality, this might be a tougher pickup than Republicans would like. We currently rate this contest as a Tossup

3: Arizona (Kyrsten Sinema, Independent)

Arizona might well be the most chaotic Senate race of 2024. Incumbent Democrat Kyrsten Sinema, first elected in 2018’s blue wave, left the Democratic Party to become an independent. She’s indicated she’ll run for re-election, but it’s not certain if she will yet. Democrats appear likely to nominate Ruben Gallego, a hardcore progressive from the Phoenix area. Gallego’s political views fall well outside of the moderate mainstream that propelled Sinema and Mark Kelly to office. With the left-leaning vote potentially split, this would set up Arizona as a strong pickup opportunity for Republicans.

The problem? Candidate quality. The Arizona Republican Party has descended into lunacy, and most of their potential 2024 nominees – Kari Lake, Mark Lamb, and Blake Masters – are ideologically repulsive to Arizona voters. Moreover, Masters and Lake both lost very winnable races in 2022. A race between Sinema, Gallego, and a hardcore Trump Republican could well end in the Democratic Party’s favor. With all the factors considered, we think this race is a clear Tossup.

2: Ohio (Sherrod Brown, Democrat)

Once America’s premier swing state, Ohio has now firmly solidified itself as a red state. The only remaining statewide elected Democrat, Senator Sherrod Brown, has a tough fight ahead in 2024. The populist Brown, a reliably liberal vote, has held office for three terms and has reasonably strong approval ratings. However, Republicans have a strong potential field of challengers; Cleveland-area state senator Matt Dolan has already announced, and Secretary of State Frank LaRose has also expressed interest. Both come from the establishment wing of the party, potentially blunting the risk of a J.D. Vance-style underperformer.

Importantly, Brown’s win in 2018 can be seen in hindsight as somewhat underwhelming – a 6.8% win over Jim Renacci, a notoriously poor campaigner, in the best Democratic midterm since Watergate. We have this race as a Tossup, but a strong Republican field and a changing Ohio means that this could shift sooner rather than later.

1: West Virginia (Joe Manchin, Democrat)

West Virginia isn’t just the state we have as most likely to flip – it’s the only state we have outright favored to flip at the moment. Incumbent Democrat Joe Manchin has withstood a radical shift in the state, as it has moved from reliably Democratic to solidly Republican over the last 30 years. But Manchin, the last statewide Democrat elected in West Virginia, is now wildly unpopular. The most recent poll has Manchin with an approval rating of only 39%. This simply isn’t enough; in order to win a state like West Virginia – especially in a presidential year – Manchin needs to not just be popular, but extremely popular.

As of the writing of this article, it’s unclear if Manchin will run for re-election. However, one Republican seems nearly certain to run. Popular Governor Jim Justice is publicly eying the seat, and his sky-high approval ratings would make him the resounding favorite. A recent poll has Justice 32 points ahead of his nearest challenger in the primary and leading Manchin by 10% in the general. We have this race at Likely Republican. Manchin still has time to try and recover his approval ratings, but it’s hard to envision a scenario where he holds on.