The 2026 Senate battle centers on roughly 10 competitive races that will determine whether Democrats can net the four seats needed for a majority. Maine, North Carolina, Michigan and Georgia are the core battlegrounds, but contests in Ohio, New Hampshire, Iowa, Alaska and Minnesota also matter. Costly primaries and heavy ad spending will shape the map, while health care, the economy and candidate quality will drive voter decisions.
10 Senate Races That Could Decide Control Of The Senate In 2026
Susan Collins, R-Maine, and Jon Ossoff, D-Ga., are two of the most vulnerable senators up for re-election in 2026. (Getty Images)
The 2026 fight for control of the U.S. Senate is sharpening as both parties recruit high-profile candidates, eye vulnerable seats and prepare for costly primaries and ad battles. Democrats need a net gain of four seats to win a majority — a path that likely requires flipping multiple competitive states — while Republicans aim to defend key battlegrounds and potentially expand their edge.
Why These Races Matter
Several factors will determine control of the Senate next year: candidate quality, the outcome of sometimes bruising primaries, local issues such as health care and costs, and the ability of each party to motivate voters — especially in states where the president’s presence on the ballot varies.
Core Battlegrounds
Maine
Sen. Susan Collins remains the lone Republican senator from New England and is the GOP’s best chance to hold a seat in a state the Democratic presidential nominee carried by nearly seven points in 2024. Collins has signaled she plans to run. The Democratic primary between Gov. Janet Mills and military veteran Graham Platner will decide Collins’s opponent; Mills has built party support around electability while Platner runs as an anti-establishment progressive and has faced controversies that he has publicly apologized for.
North Carolina
With retiring Sen. Thom Tillis leaving an open seat, Democrats recruited former Gov. Roy Cooper, while Republicans nominated Michael Whatley, the former RNC chair who has President Trump’s endorsement. North Carolina is a consistent battleground — Trump won it in 2024 by a narrow margin — and both sides view the race as winnable, making it one of the most expensive expected contests.
Georgia
Sen. Jon Ossoff is the only Democratic senator running for re-election in a state President Trump carried in 2024, and Republicans target him aggressively. Georgia’s GOP primary — a three-way contest among Reps. Buddy Carter and Mike Collins and Derek Dooley (who has Gov. Brian Kemp’s endorsement) — will shape the general election matchup. Ossoff is emphasizing health care, the economy and ethics as central themes of his campaign.
Michigan
Sen. Gary Peters’s retirement opened a competitive Michigan seat. Republicans have coalesced around former Rep. Mike Rogers, while Democrats are deciding among Rep. Haley Stevens, state Sen. Mallory McMorrow and physician Abdul El-Sayed. The Democratic primary has highlighted divisions over manufacturing policy and foreign policy, and will not be resolved until late summer.
Other Races To Watch
Ohio
Democrats landed a recruiting coup when former Sen. Sherrod Brown announced a challenge to GOP Sen. Jon Husted in a special election to finish a two-year term. Brown’s name recognition makes Ohio competitive despite its recent swing to the GOP.
New Hampshire
With Sen. Jeanne Shaheen retiring, New Hampshire becomes an open, competitive race. Senate Republicans back former Sen. John Sununu, who faces a primary from Scott Brown; Rep. Chris Pappas is the leading Democratic contender. Both parties view this contest as pivotal in the Northeast map.
Iowa, Alaska, Minnesota
Open-seat and recruitment dynamics make these states worth watching. In Iowa, GOP Sen. Joni Ernst’s retirement has produced a crowded field; Republicans rallied around Rep. Ashley Hinson while Democrats field candidates including state Rep. Josh Turek and state Sen. Zach Wahls. In Alaska, Democrats hope former Rep. Mary Peltola may run against Sen. Dan Sullivan. Minnesota’s contest features potential GOP recruits (including Michele Tafoya) and a Democratic primary between Rep. Angie Craig and Lt. Gov. Peggy Flanagan to replace retiring Sen. Tina Smith.
Primaries, Spending And The Path Forward
Primaries in several states — including Texas, where a three-way GOP contest could force a runoff, and Michigan, New Hampshire and others — may be bruising and expensive, shaping who emerges for the general election. Past ad spending in marquee races has exceeded hundreds of millions of dollars, and operatives on both sides expect heavy investment again in 2026.
Ultimately, control of the Senate will come down to turnout, candidate matchups and whether national and local issues — especially health care and the economy — favor one party. The next year’s calendar of primaries and fundraising will provide clearer signals about which way the balance of power may tilt.
This article was adapted from reporting originally published on NBCNews.com.
