Washington — The key contests that will determine who wins control of the Senate are now set for the fall midterm elections, as the 2026 primary season wraps up.Republicans are fighting to hold onto their majority, where the GOP currently controls 53 seats. The map this cycle initially appeared to be working in their favor, since most of the 22 seats the GOP is defending are in states that President Trump won by comfortable margins in 2024. But the unpopular war with Iran and persistent affordability issues have helped make several Republican-held seats increasingly competitive, while Democrats are trying to defend a handful of other seats from possible GOP flips.To secure a majority, Democrats would need to net four seats in November's election. These are the 12 key Senate races to watch:Maine: Susan Collins vs. Troy Jackson
Maine GOP Sen. Susan Collins, left, and Maine Democratic candidate Troy Jackson.
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The Maine Senate race was closely watched even before personal controversies arose around the Democratic nominee, oyster farmer Graham Platner. In July, he bowed out of the race in the wake of a sexual assault allegation. Maine Democrats then rallied around Troy Jackson as their nominee to take on GOP Sen. Susan Collins in November, in a race that once appeared to be Democrats' most straightforward opportunity for a pickup. But the five-term senator has overcome difficult reelection fights in the past, and Democrats' chaotic primary process could complicate the picture. Jackson, 58, is a fifth-generation logger who was previously president of the Maine state Senate and bills himself as a champion of the working class. Sen. Bernie Sanders backed Jackson's failed run for governor — he finished third in the Democratic primary in June.
