Election calculator: Who will control the Senate after the midterms?

The battle for the Senate in the midterm elections will determine how much room Donald Trump has to maneuver during the second half of his term: no legislation reaches the White House without first passing through the upper chamber.

Republicans currently hold 53 seats, while Democrats have 47, including the two independents who vote with them. To regain control, Democrats need a net gain of four seats. If they succeed, they could block Trump’s appointments and decide which bills come to the Senate floor, even if they fail to win back the House.

The starting point

Republicans have more to defend: of the 35 seats up for election, 22 are theirs. In North Carolina, Thom Tillis is retiring, and polls suggest the seat is tilting toward the Democrats. But the Democratic Party is also on the defensive in its own territory: Michigan and New Hampshire are open races following the retirements of Gary Peters and Jeanne Shaheen, while in Georgia, Jon Ossoff is seeking reelection in a state Donald Trump won in the 2024 presidential election.

If each party wins the races currently leaning in its favor, Democrats would hold 48 seats and Republicans 47. According to current projections, a handful of states remain toss-ups, including Alaska, Iowa, Maine, Ohio and Texas, all currently held by Republicans (see below the map for more information on these contests). Democrats need to win three of them to reach 51 seats; Republicans would only need to hold on to three to retain control, since in the event of a 50-50 tie, Vice President JD Vance would cast the tie-breaking vote.

Now it’s your turn

Assign each state to a party using the map or the cards below and decide who will control the Senate. Click the “Reset” button to return to the starting point.

Quick guide to the states that will decide the Senate

Republican Dan Sullivan is seeking a third term in a state Trump won by 13 points. He faces Democrat Mary Peltola. Alaska uses an open primary system and ranked-choice voting in the general election, a format that has produced surprises before: in 2022, it helped Peltola win the state’s sole seat in the House of Representatives.

Republican Joni Ernst is not seeking a third term, meaning Iowa will elect a new senator: either Republican Ashley Hinson or Democrat Josh Turek. Donald Trump carried the state by 13 points, and Democrats have not won a Senate race there since 2008.

Susan Collins is the only Republican defending a Senate seat this year in a state won by Kamala Harris. She is seeking a sixth term and faces Democrat Troy Jackson, after Graham Platner dropped out of the race. Collins has a reputation for political survival: in 2020, polls had her trailing, yet she won by nearly nine points even as Joe Biden carried Maine.

A special election will determine who serves out the remainder of JD Vance’s term through January 2029 after he vacated the seat to become vice president. The seat is currently held by Republican Jon Husted, who was appointed to the position. Donald Trump carried Ohio by 11 points, but former Democratic senator Sherrod Brown, who lost reelection in 2024, is seeking a comeback.

Democrats have not won a Senate election in Texas since 1988, and Donald Trump carried the state by nearly 14 points. Even so, the seat remains competitive heading into November: Senator John Cornyn lost the Republican primary to Ken Paxton, who will face Democrat James Talarico in the midterm elections.

Methodology: Clicking on the map or on the Dem./Rep. buttons assigns the seat to a party. The starting point reflects the consensus forecast: seats rated Lean/Likely/Safe D count toward the Democrats; Lean/Likely/Safe R toward the Republicans; toss-ups are assigned to the incumbent party. A majority requires 51 seats (or 50, with the vice president casting the tie-breaking vote in a 50-50 Senate).

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