Senate Republicans are likely to be more on defense than offense in 2026, but the field will be small unless and until the environment deteriorates.
Senate Republicans are likely to be more on defense than offense in 2026, but the field will be small unless and until the environment deteriorates.
I t’s early to say what the 2026 Senate elections will look like. And yet, it is important. With 53 Senate seats, Republicans only need to avoid a net loss of three or more seats in order to hang on to control of the chamber through the remainder of Donald Trump’s term. Realistically, they need a one or two-vote margin of error in order to be able to reliably confirm judges and pass other priorities that require 51 votes (counting Vice President JD Vance’s tiebreaking vote). Many decisions that will be made in the next two years — especially regarding the potential retirement of Supreme Court justices — are likely to be shaped by expectations about whether Trump has two or four years with a Republican Senate. So, we must start thinking about it today.
There are three key elements to a Senate election cycle: the political environment, the map, and the candidates.
The Environment
Long experience has taught us the overwhelming importance of the national political environment in Senate races, which tend to be driven by a wave dynamic in one direction or another. Usually, in midterm elections, the wave is against the president’s party, and its strength depends upon the extent of the president’s unpopularity. Popular presidents, such as George W. Bush in 2002 and Bill Clinton in 1998, tend to be immune, but things can get shockingly ugly for second-term presidents after their triumphal reelection, such as Democrats losing nine seats under Barack Obama in 2014 or Republicans losing 13 seats (plus losing elections for two newly created seats for Alaska and Hawaii) under Dwight Eisenhower in 1958.
The trend hasn’t always exactly held in the simplest fashion: Trump in 2018 and Joe Biden in 2022 each saw their party gain Senate seats when the president was unpopular, while Ronald Reagan’s party lost eight Senate seats and control of the chamber in 1986 while Reagan had a 63 percent approval rating and only 29 percent disapproval. The reasons for bucking the trend can vary. Reagan’s party lost seven Senate races decided by less than two points. Republicans in 2018 had a very favorable map, with Democrats defending many seats in deep-red territory, and a polarizing Supreme Court fight over Brett Kavanaugh helped Republicans win Senate races in the same environment where they were bleeding House races and governorships. Democrats in 2022 benefitted from unusually bad Republican candidates, Trump’s status as a kind of parallel incumbent, and a voting base fired up about the Dobbs decision.
At this writing, Trump’s approval and disapproval ratings in the RealClearPolitics average are, respectively, 49.2 percent and 47.8 percent. That’s not great for a president still in his honeymoon phase (Obama was around +7.5 at this point, and George W. Bush was around +5), but it’s remarkable for Trump, whose approval rating was underwater by double digits for most of his first term, including at the time of the 2018 midterms.
We don’t know yet how well Trump’s popularity with his new coalition will hold up over the next year and a half, much less how many of his low-propensity-voting supporters will turn out in 2026 without him on the ballot. But we’re getting a preview already of how the dynamics of a midterm tend to work against an incumbent. Look at New York Governor Kathy Hochul, who is massively unpopular. She faced a stiff challenge in 2022 from Lee Zeldin, one she still won by 6.4 points. Her unpopularity acted as an accelerant for the bad environment emanating from Joe Biden’s White House, helping Republicans have a great day in House races as well as state and local elections across New York. Just this week, however, Trump has allowed Hochul to twice posture herself as standing up to “King” Trump — on her threat to remove Eric Adams as mayor and on her otherwise roundly despised congestion-pricing plan. Hochul may yet be doomed in a Democratic primary, but if she spends the next year and a half polarizing state and local issues into a referendum on Trump (who even in spite of big gains in 2024 still lost New York by twelve points), it will be good for New York Democrats.
The Map and the Candidates
That brings us to the other questions that dominate Senate races: Who is running and where? At first glance, the map can look menacing for either party depending upon how you read it. Republicans are defending 22 seats to Democrats’ 13, so right off the bat, the GOP stands to lose more on a bad night than it could gain on a good one. However, two of the three announced retirements so far are Democrats, and while Republicans are defending one seat in a state won by Kamala Harris, Democrats are defending two seats in states won by Trump in 2016 and 2024.
A better way to carve up the map is to divide it into buckets based upon what kind of political environment is apt to put each seat at risk.
The Purple Map
Start with seats that are likely to be endangered in a neutral political environment where Trump’s approval and disapproval ratings are about even and there’s no particular driving force turning voter enthusiasm up or down on either side.
Maine (R-Susan Collins): Senators who are far out of step with the partisan tilt of their states have been ruthlessly purged in the past several cycles. There are currently ten Democratic senators in states won by Trump in 2024, but all ten of them are in swing states that Trump lost in 2020. The most Republican of those states in 2024 was Arizona, which Trump carried by 5.5 points, but 2026 will be the first Senate election cycle since 2014 without a Senate race in Arizona.
The only Republican senator representing a state won by Kamala Harris is Susan Collins. Indeed, there are only two other Republican senators representing states won by Joe Biden in 2020: Ron Johnson in Wisconsin (up for reelection in 2028) and Dave McCormick in Pennsylvania (up in 2030).
Maine is blue, but not deep-blue. It elected a MAGA-style Republican (Paul LePage) as governor in 2010 and 2014, albeit against opposition divided by major third parties, and Trump lost it by 6.9 points in 2024, nine points in 2020, and 2.96 points in 2016. Angus King has won his Senate races by 17.4 points in 2024, 19.1 points in 2018, and 22.2 points in 2012 since the retirement of liberal Republican Olympia Snowe. Collins was just 44 when she was elected to the Senate, so in spite of her long tenure — if reelected, she’d be Maine’s longest-serving senator — she’s still likely to seek reelection for at least one more term at age 72. She has proven her ability to win against the tide in difficult cycles: She won by 22.8 points in 2008 while John McCain was losing Maine by 17, and she won by 8.6 points in 2020, running 17 points ahead of Trump.
Collins has spent years burnishing her credibility as a Senate maverick who can deliver for Republicans on some tough votes, but also dissent loudly on others. Recently, her stands against Matt Gaetz, Pete Hegseth, and Kash Patel may enrage the MAGA faction, but they also remind Maine independents why they cross the aisle for her. Yet she also voted to confirm RFK Jr. and Tulsi Gabbard, worse choices than Hegseth and Patel but with more appeal to independents.
Anyone but Collins would lose this seat in a heartbeat. She may face her toughest challenge yet if term-limited governor Janet Mills runs. Another potential Democrat, Representative Chellie Pingree, lost to Collins by 17 points in 2002, but there’s been a lot of water under the bridge since then.
So long as Collins is running, she should be considered the favorite in a neutral environment — but this will be a tough race. The worse the environment is for Republicans, the likelier they are to lose this seat.
Georgia (D-Jon Ossoff): There’s only one obvious pickup opportunity for Republicans this cycle, and that’s Georgia. It’s no longer the safe Republican haven that it was between 2000 and 2018, when the GOP won every single major statewide race for two decades. But Joe Biden’s 2020 victory in the state and three Democratic victories in Senate races in 2020 and 2022 — all of them requiring a runoff — look more like a fluke today. Brian Kemp’s Republicans have continued to dominate Georgia politics at the state level. While Trump won Georgia by 2.2 points in 2024, House Republicans won the statewide popular vote by 5.2 points. And now, instead of a fatally flawed candidate such as Herschel Walker, Republicans seem likely to run Kemp himself, who is term-limited after a seven-point stomping of Stacey Abrams in 2022. Kemp has proven himself as a conservative; he’s proven himself as a statewide winner; he’s proven himself as a fundraiser; and he’s proven himself as a man who can stand up to Trump and live to tell the tale.
In 2020, Ossoff lost by 1.8 points to David Perdue on Election Day, but beat Perdue by 1.4 points in a runoff held on January 5, 2021, in the midst of Trump’s election challenge. When Kemp faced Perdue in a primary the following year, he won by 52 points.
The 38-year-old Ossoff, who thus far has done absolutely nothing in the Senate to distinguish himself from a generic Democrat, will need help either from the national environment or from Republicans not running Kemp. In a neutral environment, facing Kemp, Ossoff would be favored to lose.
The Light Blue Map
Next, let’s suppose an environment that is modestly favorable to Democrats, such as Trump with an approval rating around 46 percent and losing some of his tenuous support among high-turnout suburbanites, who gave him another chance in 2024 after uniting against him between 2018 and 2022.
North Carolina (R-Thom Tillis): North Carolina is a red state, but only by a slim enough margin that it’s easy to end up blowing statewide races there in the same way that Republicans have done in Georgia and Arizona. At the presidential level, the largest Republican margin of victory in the four elections since Obama won it in 2008 has been 3.7 percent. Republicans also haven’t lost a Senate race in North Carolina since 2008, but their margins of victory in the last four races have never exceeded 5.7 points. Tillis is not a particularly impressive political talent, having won by 1.6 points in 2014 and 1.8 points in 2020. But as Mark Robinson illustrated in losing the governor’s race in the state in 2024 by 15 points, North Carolina Republicans are capable of doing a lot worse.
Tillis will be a major target, and if the environment is even modestly unfavorable, he could lose. Democrats’ biggest potential recruit is former governor Roy Cooper, although conservative states have often been far less willing to elect Democrats to the Senate than as governors (the same goes the other way, as Larry Hogan could testify).
The problem for the Democrats: That’s the end of the soft targets. If they can take down Tillis and Collins while reelecting Ossoff, they can take the Republican conference down to 51 seats, one of which is Lisa Murkowski. But they will need to take out a harder target to win back the majority.
The Light Red Map
Michigan (D-Open): Michigan has been tantalizing for Republicans. Previously considered the bluest of the blue-wall states, it has now been won twice by Trump — but in both cases, with less than a majority of the vote statewide. Republicans have run progressively closer in the last three Senate elections, losing by 6.5 points and 1.7 points behind John James in 2018 and 2020, and by just 0.3 points behind Mike Rogers in 2024.
But Michigan isn’t Georgia. Democrats swept the state in 2022 behind Gretchen Whitmer and a statewide pro-abortion referendum, albeit against a colossally disorganized Michigan GOP. Republicans won back the state’s house in 2024, but the many near misses and few narrow wins for the party statewide suggest that everything really needs to go just right for Republicans to carry Michigan. Even a modestly blue environment could yield another heartbreakingly close loss.
There are cases that can be made for optimism. Michigan has an open seat in 2024 with Gary Peters retiring. Whitmer is ruling out a Senate run, and if Pete Buttigieg runs and wins the nomination, that will test the enthusiasm of Michigan’s unusually populist Rust Belt electorate for a smug transplanted management consultant who lost his only prior bid for statewide office by 25 points.
The Rustpolitik approach of the Trump/Vance campaign worked in 2024 — barely, in states such as Michigan and Wisconsin. It will be put to a much sterner test of the theory in Michigan in 2026, when there will also be an open governor’s race to succeed Whitmer, open races for state attorney general and secretary of state, two state supreme court seats, both houses of the Michigan legislature, a state constitutional convention, and a potentially large slate of ballot initiatives.
Whom to run, with so many open offices? Probably not James, who is fighting for a House seat he has continued to hold narrowly. Hopefully not Tudor Dixon, who is teasing a bid but lost by double digits to Whitmer in a shambolic 2022 campaign. Republicans might just run Rogers again, given that he ran respectably in 2024 and even ran ahead of Trump with black men and in populous blue counties like Washtenaw and Kalamazoo. But that entails hoping that the race will go better rather than worse for Republicans than it did in 2024.
The Blue Wave Map
Florida (R-Ashley Moody); Iowa (R-Joni Ernst); Texas (R-John Cornyn); Ohio (R-John Husted); Kansas (R-Roger Marshall); Kentucky (R-Open); South Carolina (R-Lindsey Graham); Alaska (R-Dan Sullivan); Louisiana (R-Bill Cassidy).
None of the seats on this list would be especially endangered in anything like a neutral environment. But waves against the incumbent party can be unpredictable. Moody and Husted are both new in their seats, but experienced statewide candidates. It’s easier to picture Cassidy being defeated by a fellow Republican in Louisiana’s jungle primary system than a Democrat winning the seat. Texas, Kansas, and South Carolina are all the sorts of places where Republicans could be vulnerable due to complacency against a good opponent in a bad environment. Kentucky, with Mitch McConnell’s retirement, remains a likely safe seat, but open seats can surprise. Sullivan is probably the safest incumbent on this list.
The Red Wave Map
Minnesota (D-Open); New Hampshire (D-Jeanne Shaheen); Virginia (D-Mark Warner); New Mexico (D-Ben Ray Luján); Colorado (D-John Hickenlooper).
If a Democrat was in the Oval Office, all of these seats could be on the table (with Hickenlooper being the safest). A few of them might still be, if things are really going spectacularly for Republicans in 2026. But that’s an unlikely scenario. Minnesota is the most enticing, with Tina Smith retiring. If this is a good environment for Democrats, then it’s prudent for Smith and Peters to quit when the odds of keeping the seat in friendly hands is highest — but this far out, that’s a gamble. Minnesota, however, remains a heavier lift for Republicans than Michigan. Republicans should be smarter than to run Royce White again, after the ex-basketball player with a truckload of oppo baggage lost an uncompetitive race by 16 points to Amy Klobuchar in 2024. Peggy Flanagan, Tim Walz’s lieutenant governor, is running, and may face a crowded field of Democratic aspirants. Among the potential Republicans mulling a run are former sportscaster Michele Tafoya and state senator Julia Coleman, the daughter-in-law of Norm Coleman. Former governor Tim Pawlenty, an ideal fit for the state during the Bush era, will not attempt a comeback in a more populist era. In New Hampshire, Scott Brown is teasing another run after losing to Shaheen in 2014 in a red-wave environment.
* * *
The downsides for Republicans in 2026 are bigger than the upsides. For now, however, the likeliest outcome of the next cycle of Senate races is trench warfare ending in a modest erosion of the Republican conference to 51 or 52 seats. As always, however: Events, dear boy, events.