Believe it or not, we’re only about a year out from the thick of the next major American election, so we’re emerging from our restful summer (did anything interesting happen while we stepped away?!) and turning our eyes to the state of the upcoming 2024 Senate race.

Let’s start with blunt math. The main draw this cycle, of course, won’t be at the congressional level at all. The presidential election will dominate the airwaves, the discourse, and have a pervasive impact on down-ballot races. It will also make a big difference when it comes to control of the Senate, since the vice president breaks ties when the chamber is split 50/50.

At the moment, Democrats control 51 Senate seats and the vice presidency – though this includes three independent senators who caucus or are otherwise ideologically aligned with the party. Of those three independents, two are reliable Democratic votes who choose to avoid the party label for no good reason but use it to get reelected (yes, I’m in a mood about it): Maine’s Angus King (who voted with President Biden’s agenda about 99% of the time in the 117th Congress, which wrapped up this January) and Vermont’s Bernie Sanders (voting with the president about 91% of the time that Congress). The last independent is an even more reliable Democratic vote (100% in the last Congress) but who decided to leave the party at a very strange time – right after Democrats overperformed in the 2022 midterms and even picked up a seat in the Senate. That, of course, is Arizona’s Kyrsten Sinema. 

With functionally 51 Democratic senators, this means Democrats can afford to lose one seat and still keep control of the Senate… so long as they also win the presidential election. A loss of two seats, or a loss of the presidential election and just one seat, and Democrats will have lost the chamber. Advantage Democrats? Probably not… three vulnerable Democrats whose Senate seats will be on the ballot next fall are in states that Donald Trump won twice. To make matters more dire for the party, unlike in 2020 and 2022, Democrats don’t have any good offensive options, as Republicans are only defending Senate seats in two states that Trump won by less than 10%: Florida and Texas. 

In the last two presidential elections, only one Senator – Maine’s Susan Collins, a Republican – managed to be elected despite their state’s popular vote going to a presidential candidate of the opposite party (Joe Biden won Maine in 2020 on the same ballot as Collins). Even if you assume one of the defending Democratic senators can pull that off, Democrats would still lose two seats and the Senate. However, there are a handful of other states that Biden won by less than 5% in 2020 that Democrats have to defend this cycle. Oft-mentioned states like Wisconsin, Pennsylvania, Nevada, Michigan, and Arizona all provide their own unique opportunities to Republicans (all except Nevada were won by Trump in 2016), or at least draw energy away from vulnerable Democrats elsewhere.

Having set the scene, here are the Senate races we’re watching as we approach 2024, where – as always – you can expect our standard fare of Senate ratings, analysis, and rational expectation-setting. Let’s start with the three defending Democrats…

The Defenders: Ohio, Montana, and West Virginia

A lot of attention will be focused on these three races. Ohio’s Sherrod Brown, Montana’s Jon Tester, and West Virginia’s Joe Manchin are the most seriously threatened Democratic incumbents – each hails from a state Trump won in both 2016 and 2020, though to varying degrees. What these three incumbents have in common is that they’ve avoided sharing a ballot with a Republican presidential candidate for 12 years (they were each up in 2012, when Mitt Romney carried West Virginia and Montana, but not Ohio); this will pose a unique wrinkle in a situation where Trump is increasingly likely to be on the ballot in 2024.

In Ohio, Sherrod Brown has to fight against an electoral environment that has rapidly shifted to favor Republicans over the last decade. Trump won the state in 2020 by 8%, roughly the same margin by which he won it in 2016, but – once adjusted for the national margin – Ohio has partisan lean close to R+12.5, indicating that if the national popular vote is even, a generic Republican will tend to carry the state by 12.5%. This is a big hurdle for a Democrat to overcome, so is three-term incumbent Brown up to the challenge?

Maybe! Brown, who has built a reputation as a passionate defender of blue collar workers and progressive causes, continues to perform fairly well in polls, consistently matching or outperforming his likely challengers. Of course, there’s good reason to be somewhat skeptical of polls that favor Democrats in Ohio, as polls there overrated Biden in 2020 too. All in all, Democrats are lucky Brown decided to run again – he seems to have the right stuff to win in Ohio – but this could be a close race and is almost certainly a must-win for Democrats.

Across the Ohio River in West Virginia, two-term Democrat Joe Manchin is stirring up some unusual feelings and fears. Though he has not yet committed to running for reelection, he’s not exactly been absent from the headlines over the last two years and is now actively enabling rumors about a third party presidential campaign. Put that aside for a second and assume Manchin runs for reelection and he still has to face a state that gave Biden less than 30% of its vote in 2020, delivering Trump a whopping 39% margin of victory. Given that this will be the first election since 2012 in which Joe Manchin has shared the ballot with the Republican presidential nominee – which is increasingly likely to be Trump – and Manchin voted to convict Trump in both impeachment trials, this looks bleak! Manchin’s also likely to draw a strong opponent: Governor Jim Justice. Not only is “Big Jim” one of the wealthiest politicians in the country, he’s also quite popular in the Mountain State, whereas Manchin is among the least popular senators in the country. If there is a “good” playbook in West Virginia for Democrats, they’re probably trying to run it already: keeping Manchin – and his record of bucking his party in words, if not on paper – on the ballot has the optics of a more competitive race, drawing Republican money and energy out of Ohio or Montana, while Manchin goes down as a willing sacrificial lamb. The only question is how much of a team player Manchin is willing to be at the end of the day.

More than half a continent away in Montana, Democrat Jon Tester is running for a fourth term. Tester, unlike Manchin, is popular, but that doesn’t mean there aren’t some hefty barriers to reelection here either. Trump won the state by about 16.5% in 2020, making it about 21% more Republican than the country as a whole. That’s better than the margin in West Virginia, but it’s not exactly good for Democrats – especially considering that Trump may be on the ballot! That said, something that may work in Tester’s favor is the size of Montana. Though geographically massive, its population is small – only about 600,000 votes were cast in the 2020 presidential election in Montana. States with smaller populations provide a heartier incumbent advantage than bigger states, and Tester has been a known quantity in Montana for the better part of two decades. Tester may also draw a weak opponent. Though Tim Sheehy, the GOP’s preferred candidate, is in the race, Tester and the Senate Democrats are probably hoping Congressman Matt Rosendale (who Tester defeated in 2018) enters the fray, dividing the Republican primary and allowing Tester to build up some more goodwill for the general.

Sunbelt Squeakers: Arizona and Nevada

To a lesser degree, Democrats need to play defense in the Sunbelt, too, as tight margins in the Southwest mean they cannot afford to completely take it for granted. 

The race that will draw the most attention in this region is Arizona, where incumbent Democratic-aligned Senator Kyrsten Sinema is… maybe running for reelection? As an independent? We don’t really know yet. Sinema’s in a bit of trouble as she lost a lot of favor with the party over the last few years, ultimately earning a censure from the Arizona Democratic Party because she did not join the party orthodoxy on eliminating the filibuster. Because of party dissatisfaction, it was widely expected that Congressman Ruben Gallego would run in a Democratic primary against her. Gallego is running and is a clear frontrunner for his party’s nomination, but Sinema is no longer a Democrat. Meanwhile, the Republicans are facing the prospect of another statewide run by news anchor and 2022 gubernatorial nominee Kari Lake, who is controversial, to say the least, but probably a frontrunner for her party’s nomination nonetheless. 

So what’s going to happen? There are three possibilities. If Sinema does not run, Gallego will likely face a far-right Republican, and likely will win – this would most closely parallel the 2022 Senate race in the state, where incumbent Democratic Senator Mark Kelly handily defeated Republican Blake Masters, buoyed by the fact Arizona is a moderate state trending more Democratic. If Sinema makes the turnaround of a lifetime and decides to run against Gallego in the Democratic primary, then Gallego – who significantly outpolls Sinema in most polls in both primary and general election matchups – probably walks away the nominee and faces down a Republican one on one, again with an advantage in the general election. But the nightmare scenario (for everyone!) is if it turns into a three way race between Gallego, Sinema, and a far-right Republican like Kari Lake. It’s become increasingly clear that Sinema doesn’t have much of a path towards reelection (there’s a reasonable question as to who her base is, exactly, anymore – moderate Republicans?), and she tends to get less than 20% in polls of three-way matchups. But she could pull votes away from the Democratic candidate too, making this a nail-biter for Democrats in a race they otherwise wouldn’t need to focus as heavily on. If the three-way race scenario unfolds, Arizona will become the most exciting race of the cycle.

Across the Colorado River in Nevada, Democrats will also be playing defense. We wouldn’t really do ourselves justice if the Silver State wasn’t on this list. Its elections have dominated a lot of our coverage in the last few years, and for good reason. Though Georgia was the tipping point state in the 2022 race for control of the Senate (in that it provided the 50th Senator to Democrats, giving Vice President Kamala Harris the power to break the tie in the chamber), it was Nevada that was the closest race. This was a drum we beat for months in the lead up to that election (and in the year before), and it proved to be an astute one! Nothing about the 2022 midterms and the high profile state in Nevada should convince you the state is safe for Democrats, as the margins there continue to narrow, and the state delivered the only top-of-the-ticket defeat for an incumbent Democrat in 2022.

Incumbent Democrat Jacky Rosen is running for reelection and is likely to face one of three candidates: Army veteran and 2022 Senate candidate (not nominee) Sam Brown, 2022 secretary of state nominee Jim Marchant, or former U.S. Ambassador to Iceland Jeffrey Ross Gunter. National Republicans want Brown, as Marchant has a lot of baggage and Gunter’s claim to fame is a government report that as ambassador he fostered a “threatening and intimidating environment.” Either way, Rosen is probably still favored in a presidential year, but whether this is a lean Democrat race or a “tilt” Democrat race will depend on if Brown gets the GOP nomination.

Midwestern Malaise: Wisconsin and Michigan

We’ve spent a lot of ink (err… pixels) over the years about the exciting and increasingly polarized politics in the Midwest, so it may surprise you to see us use the word “malaise” to describe the prominent Midwestern Senate races in 2024. That said, the elections in 2018 are a good gauge of expectations: despite the fact that Trump narrowly won states like Wisconsin and Michigan in 2016 (and Biden carried both, though  by relatively slim margins compared to previous Democratic nominees), the Democratic incumbents in these states have not been particularly at risk over the last six years. Incumbent Wisconsin Democrat Tammy Baldwin defeated her Republican challenger by nearly 11% in 2018 and Michigan incumbent Debbie Stabenow defeated Republican John James by 6.5% that same year.

Though the 2020 Senate election in Michigan was a bit of a nailbiter – James came within less than 2% of defeating incumbent Gary Peters – and Wisconsin Republican Senate incumbent Ron Johnson came within 1% of defeat in 2022, the 2024 races aren’t likely to have the same complicating factors that both of those races have. Baldwin is up for reelection, and is a favorite in the general election in Wisconsin given her positive reputation (contrast that to Johnson, who does not have a stellar reputation and nearly lost) and the fact that Republicans have struggled to recruit a strong candidate for this race. Advantage Democrats. 

The race in Michigan may be more interesting because Stabenow is retiring, leaving an open seat… but one Democratic Congresswoman Elissa Slotkin is likely to receive the nomination for, given a wide polling and fundraising lead thus far. Meanwhile, the Michigan Republican Party is undergoing a bit of a self-imposed crisis after a bruising defeat in the 2022 midterms and seems unlikely to rally around a strong candidate. Given Slotkin hails from a swing district and likely begins with a head start in a state where Democrats have reinvested a lot of energy, Democrats are favored in the Great Lake State too.

So why include them in this list? What we’re watching here is whether Democrats can propel favored status and energy in these Senate races into positive effects at the presidential level. Wisconsin will be hard-fought over in the presidential race, so whether Democrats can churn up Senate excitement, or Republicans can get competitive candidates on the ballot, could make all the difference in a state where a few thousand votes could make all the difference.

Cruzin’ for a Bruisin’: Maybe Texas, Maybe

Last but not least is the inverse of the Midwestern malaise. Earlier this summer, we inquired as to when Democrats would have a reasonable chance of winning Texas. Given the state was about 10% more Republican than the nation as a whole in 2020 and extrapolating on data from presidential races in the 21st century we found that Texas would reasonably be in reach for Democrats in about a decade. A massive state which is moving about 1% towards the Democratic Party every four years, in 2024 the state will likely only be about 9% to the right of the nation. This means that Democrats would need a compelling national victory beyond even the 2008 Obama landslide to put the state in play.

That probably won’t happen in 2024 given Biden’s tepid approval ratings and political polarization, but Ted Cruz isn’t exactly the strongest candidate in the world either. He notably came within 3% of losing reelection in 2018, and his approval rating leaves a lot to be desired in a state where the GOP has become a bit complacent. Cruz has also amassed a lot of baggage since 2018, brashly objecting to the certification of the 2020 presidential election, enduring scrutiny regarding his role in the plot that sought to overturn the same election, backtracking on whether January 6 was “terrorism” (he later said that was a “sloppy” and “dumb” description), and – somehow, the most damning of all – taking an infamous trip to Cancun as Texans faced a crippling winter storm in 2021. 

Democrats are set to field former Tennessee Titans linebacker and current Congressman Colin Allred to take on Cruz, who could at least draw some Republican attention towards Texas and away from Democratic targets in some of the other races mentioned above. Though Allred is a strong candidate in a state where Democrats are anxious to build their bench beyond Beto O’Rourke, the fact that Texas is probably the best pickup opportunity for Democrats in 2024 is a bleak prospect, foreshadowing an ugly wipeout in the 2024 race for the Senate.