The 2026 midterm cycle is shaping up to be a genuine battle for Senate control. Democrats are banking on the traditional momentum that opposition parties tend to carry into midterms, while Republicans are counting on a favorable map to hold their ground and potentially expand their majority.
Of the 33 Senate races on the 2026 calendar, most will play out in reliably red or blue territory. But roughly a dozen seats could realistically change hands under the right national conditions, and eight of them sit squarely in toss-up territory.
North Carolina tops the list. The Tar Heel State has a well-earned reputation for producing some of the costliest Senate races in American history, and this cycle looks no different. Senator Thom Tillis, a Republican, is retiring, opening the door for a real fight.
As originally reported, Democrats landed their preferred recruit in former Governor Roy Cooper, while Republican National Committee co-chair Michael Whatley, a former North Carolina GOP chairman with Donald Trump’s endorsement, secured the GOP nomination without much trouble.
The early numbers heavily favor Cooper. The RealClearPolling average gives him a 6.8-point lead, with some individual polls showing him up by as many as nine points. Name recognition is widely seen as a key driver of that edge. Cooper also holds a commanding fundraising lead on the candidate side, pulling in $13.8 million in the first quarter compared to roughly $5 million for Whatley.
That said, Republicans are not sitting on their hands. The Senate Leadership Fund has pledged at least $71 million in outside spending to boost Whatley and hammer Cooper, which could meaningfully tighten the race before November. A recent Quantus Insights poll found Cooper leading 48.6 percent to 43.8 percent, a margin of 4.8 points that falls close to the survey’s margin of error.
Maine is the other race drawing intense national attention. Senator Susan Collins is seeking a sixth term after first winning election in 1996. She is the longest-serving senator in Maine history and the last Republican in New England’s entire congressional delegation. Her record as a moderate who crosses the aisle on issues like infrastructure and health care has helped her survive in a state that has voted Democratic in recent presidential contests.
Her likely opponent is Graham Platner, a progressive candidate and close Bernie Sanders ally who became the presumptive nominee after Governor Janet Mills dropped out in late April.
Current polling shows Platner ahead, with RealClearPolling’s average from February through early April giving him a lead of 47.6 percent to 40.0 percent, with about 12 percent of voters still undecided. But analysts are not ready to write Collins off. She has a consistent history of closing strong and outperforming polls in Maine, where ticket-splitting is a genuine cultural tradition.
Money is flowing heavily into the race on both sides. Through March 31, Collins had raised $13.2 million and held more than $10 million cash on hand. Platner raised nearly $12 million and actually outspent both Collins and his primary rival on television in the first quarter. Total ad spending has already broken Maine primary records.
With months still to go, these races are far from settled.