The 2026 primary season has ended, setting the November contests that will determine control of the U.S. Senate. Republicans currently hold 53 seats and are defending 22, most in states President Trump won comfortably in 2024. But the unpopular war with Iran and persistent affordability concerns have made several Republican-held seats more competitive, while Democrats must defend several vulnerable seats. Democrats need to gain four seats for a majority. The key races are Maine, Michigan, Ohio, Alaska, Texas, Iowa, Georgia, New Hampshire, North Carolina, Minnesota, Kansas and Nebraska. Independent election handicappers generally rate Maine, Michigan, Ohio and Alaska as toss-ups; Texas is also rated a toss-up, while Iowa is rated a toss-up by The Cook Political Report and leaning Republican by the University of Virginia's Center for Politics. Georgia, New Hampshire, North Carolina and Minnesota lean or are likely Democratic, while Kansas and Nebraska are rated likely Republican.