The prognosis for the Republican Senate majority is dire, as well-funded Democratic challengers put red states in play and GOP incumbents feel dragged down by President Trump’s faltering reelection bid.

Senate Republicans are clinging to a three-seat majority. They are poised to pick up one Democratic-held seat in Alabama and threatening to flip another in Michigan. But it all starts to come apart from there. Incumbent Republicans are endangered in Arizona, Colorado, Iowa, Maine, and North Carolina; on their heels in Georgia and Montana; and facing the prospect of major upsets in Alaska and South Carolina. Republicans could also lose an open-seat contest in ruby-red Kansas.