The Numbers
Republicans hold 53 seats. Democrats hold 47. Thirty-five seats are on the November ballot, including special elections in Florida and Ohio.
Republicans are defending 22 of those seats. Democrats are defending 13.
Democrats need a net gain of four seats to take a 51-49 majority. A 50-50 split keeps Republicans in control because Vice President Vance breaks ties.
Four seats is a large swing. Republicans are defending a seat in Maine, which Kamala Harris carried in 2024, and seven Republican senators are not running again (Ballotpedia).
35 seats on the ballot. Republicans defend 22. Democrats need to flip 4.
The Path to a Majority
Democrats would need to win four Republican-held seats and hold all of their own. These four Republican-held races drew the most attention in NPR’s overview of the Senate map.
North Carolina. Senator Thom Tillis is retiring. Former Governor Roy Cooper is running. Cooper won the governor’s race in 2016 and again in 2020.
Maine. Susan Collins is the only Republican senator representing a state that Kamala Harris carried. Collins won in 2020 with 51.0% to Sara Gideon’s 42.4%.
Ohio. Former Senator Sherrod Brown is running in the special election for Ohio’s other seat after losing his own in 2024. His opponent is Senator Jon Husted, who was appointed to fill the vacancy. Brown won Ohio Senate races three times before 2024.
Texas. Ken Paxton won the Republican primary runoff over Senator John Cornyn and faces State Representative James Talarico. Texas has not elected a Democratic senator since 1988. Paxton was impeached by the Texas House in 2023 and acquitted by the state Senate.
The Seats Democrats Must Hold
Flipping four seats means nothing if Democrats lose their own. Two of the 13 Democratic-held seats on the ballot are in states Donald Trump carried in 2024 (Ballotpedia).
Georgia. Senator Jon Ossoff won by 1.2 points in a 2021 runoff. Trump carried Georgia by 2.2 points in 2024.
Michigan. Senator Gary Peters is retiring. Former Congressman Mike Rogers, a Republican, lost the 2024 race for Michigan’s other seat to Elissa Slotkin, 48.6% to 48.3%. Trump carried Michigan by 1.4 points in 2024.
Why Control Matters Beyond Vote Counts
The majority party controls three things that shape policy even when legislation is blocked by the filibuster.
Committee chairs. The majority picks who runs every committee. Committee chairs decide which bills get hearings, which nominees get votes, and which investigations happen. A Democratic Judiciary Committee chair stops confirming conservative judges. A Democratic Budget Committee chair changes what goes into reconciliation bills.
Judicial confirmations. Confirmations require a simple majority. The current Republican Senate has confirmed over 60 federal judges since January 2025. A Democratic majority stops all future confirmations for the remainder of the presidential term.
Budget reconciliation. This is the one path around the filibuster. It allows the majority to pass tax and spending legislation with 51 votes. Republicans used reconciliation to pass tax cuts.
Democrats used it for the Inflation Reduction Act. The party with the majority decides what goes through this narrow legislative channel.
The filibuster still blocks most standalone legislation at 60 votes. A 51-49 Democratic majority would not pass voting rights, gun safety, or immigration reform without eliminating or reforming the filibuster. But it would stop confirmations, control investigations, and set the budget.
What you can do now
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Know your Senate race. If you live in Georgia, Maine, Michigan, North Carolina, Ohio or Texas, one of the races above is on your ballot. Check your registration at vote.org.
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Support candidates early. Senate races are won on fundraising in the spring and summer, not in October. Small-dollar donations to candidates in May and June fund the field operations that win close races.
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Talk to people in Texas about the Paxton matchup. Texas has not elected a Democratic senator in 38 years. Paxton’s impeachment and his record as attorney general are on the public record.
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Watch Alaska and Iowa. Former Representative Mary Peltola (D) is challenging Senator Dan Sullivan in Alaska. Iowa’s seat is open because Senator Joni Ernst is not running.
Correction, October 14, 2026: An earlier version of this brief listed Nevada’s Jacky Rosen among Democrats defending seats in 2026. Nevada has no Senate race this year; Rosen is not among the senators whose terms end in January 2027 (U.S. Senate).
The brief also carried race ratings from Sabato’s Crystal Ball, the Cook Political Report and NPR. Resist Now does not publish election forecasts, so the ratings were removed.
Since publication the nominees are set: Cooper faces Republican Michael Whatley in North Carolina, Collins faces Democrat Troy Jackson in Maine after primary winner Graham Platner withdrew, Ossoff faces Republican Mike Collins in Georgia, and Democrat Abdul El-Sayed faces Rogers in Michigan (Ballotpedia). In Texas, a Marist poll of 1,139 registered voters taken September 17-20 had Talarico at 50% and Paxton at 44% (Texas Senate race guide).