Three-term incumbent Democratic U.S. Sen. Jon Tester of Montana faces perhaps his toughest reelection challenge yet on Tuesday, with control of the Senate on the line in a state that's veered sharply rightward since the 68-year-old grain farmer's first election. Republicans have pinned their hopes on Tim Sheehy, a former U.S. Navy SEAL and founder of an aerial firefighting company. Sheehy, 38, had early backing from party leaders including former President Donald Trump, clearing the political newcomer's path to win the June primary. This is the first time Tester's name appears on the same ballot as Trump, who won Montana by wide margins in 2016 and 2020. A Sheehy victory would seal Republican party dominance across the five-state Northern Plains region: Tester entered office as one of six Democratic senators in the largely rural swath of American heartland that also includes Wyoming, Nebraska, North Dakota and South Dakota. He's now the only one. The lawmaker also is the sole ...