Oct. 29, 2024, 4:30 p.m.
Much like in the past two cycles, the battle for the Senate could come down to the thinnest of margins. But with a map that already favored Republicans and put Democrats on defense, the GOP is favored to flip the upper chamber.
Entering with a slim 51-49 majority, Senate Democrats face a tougher map compared to 2020 and 2022. The caucus has to defend 23 seats, including three in states former President Trump won twice—West Virginia, Montana, and Ohio—and five of the seven presidential battleground states: Arizona, Michigan, Nevada, Pennsylvania, and Wisconsin. Senate Republicans are defending 11 seats—none of which are presidential battlegrounds this cycle. Republicans need only a net gain of two seats if Vice President Kamala Harris is elected president or a net gain of one seat if Trump wins.
Republicans are less bullish on the size of their overall boon compared to two years ago, eyeing a 51-seat majority at minimum. Democrats, on the other hand, argue they can hold onto their majority—even as the party’s virtually guaranteed to lose its West Virginia seat with independent Sen. Joe Manchin’s retirement.
The full breakdown of the next Senate could take nearly a week to be decided. Pennsylvania and Wisconsin don’t allow mail-in absentee ballots to be counted before the polls close on Election Day. Maricopa County officials estimate it could take 13 days to count all of their votes, potentially delaying a call for Arizona’s Senate race. And Nevada’s results can’t be counted until the last voter casts their ballot.
The bellwethers
Florida—known for delivering its results efficiently—could be an early sign of Senate Democrats’ potential momentum. The Democratic Senatorial Campaign Committee has few pickup opportunities this cycle, but it has invested in Florida against Republican Sen. Rick Scott, who has only won nail-biter races. Despite the state’s apparent shift to the right in recent years, a close margin could be indicative of Democrats’ chances in Texas—where more resources were allocated.
Ohio is also expected to have most of its results in by the end of the night. Democratic Sen. Sherrod Brown not only might have to overperform the top of the ticket by more than 8 points, but has to salvage his support in Northeast Ohio and run up the margins in the state’s urban counties—especially in the Democratic-growing Hamilton County.
Michigan could be an early indicator of the presidential battlegrounds due to a law change to ballot counting, likely speeding up the release of its results. Detroit City Clerk Janice Winfrey told NBC News that “90 to 95 percent” of the city’s results could be posted by 11 p.m. EST. Winning the state would help the GOP take the majority, and potentially keep it past the 2026 midterms.
The tipping point
Depending on the GOP’s performance on Election Night, the tipping point for the Senate could either be Montana or Ohio.
Despite the Senate GOP’s better chances in Montana, results are expected to trickle in both slower and later than in Ohio. Montana’s polls also close two hours and 30 minutes after Ohio’s polls close, and only about 50 percent of votes cast in 2020 were reported by midnight on Election Day, according to the Associated Press. Nearly 95 percent of Ohio’s votes were reported by the same time.
But if the race in Ohio is as narrow as it looks this year, it’s possible that Montana could be the first to put Republicans over the edge—or that it could keep Democrats in the race.
Control call
The parties differ on when a control call could be made, but it depends on how their candidates perform on the map. Republicans believe the majority could be decided as early as Tuesday night, but they can expect to wait until Wednesday if the Montana and Ohio contests are too close to call. Democrats believe it could take a week or more for Senate control to be decided, arguing it could come down to the presidential battlegrounds—and the presidency—if the party holds off the GOP in Montana and Ohio.
A Nebraska-shaped wild card has been looming over this cycle. A close call in the state could stall a Senate control call, especially if the party makes a gain in Montana but misses in Ohio. If Republicans lose Nebraska and hold 50 seats during a Harris presidency, union leader Dan Osborn, an independent who has promised to caucus with neither party, could decide the Senate majority.
