Former Representative Mike Rogers, Republican of Michigan, announced on Monday that he would run for his state’s open U.S. Senate seat, his second bid for the chamber after losing to Senator Elissa Slotkin, a Democrat, by fewer than 20,000 votes last fall.
The seat opened after Michigan’s senior senator, Gary Peters, a Democrat, said that he would not seek re-election to a third term. The race, in a battleground state that President Trump won in 2024 and Joseph R. Biden Jr. won in 2020, will help decide control of the Senate. It is expected to be among the most closely watched in next year’s midterm elections.
A statement from Mr. Rogers’s campaign on Monday, warning that Democrats planned to “pour millions of dollars” into the race, said that he would “be an ally” for Mr. Trump and that he would be the “backup” the president needed in the Senate.
Mr. Rogers, 61, is a former F.B.I. special agent and Army officer who served in Congress for 14 years, including four as chairman of the House Intelligence Committee. He left Congress in 2015 to become a talk-radio host and eventually moved to Florida. His return to Michigan in 2023 failed to appease Democrats, who labeled him a disloyal opportunist in his race against Ms. Slotkin. That tightly fought contest, in which Mr. Trump endorsed Mr. Rogers, was one of the last Senate races to be called in 2024.
Mr. Rogers is so far the only Republican to enter the 2026 race, though Representative Bill Huizenga, who has served in Congress since 2011, is expected to run. Other possible contenders include Tudor Dixon, who lost the Michigan governor’s race to Gov. Gretchen Whitmer in 2022, and Kevin Rinke, who lost to Ms. Dixon in that race’s Republican primary.
The lone Democrat to have entered the race, State Senator Mallory McMorrow, announced her candidacy this month. Ms. McMorrow gained national prominence in 2022 when she defended her liberal values in a video while also calling herself a “straight, white, Christian, married suburban mom.” Two other Democrats — Representative Haley Stevens and Abdul El-Sayed, a former health director in Wayne County, Mich. — are eyeing the race.
Several Democrats have notably decided to skip the contest. Both Ms. Whitmer, who is barred from running for re-election because of term limits, and Pete Buttigieg, the former transportation secretary in the Biden administration who moved to Michigan in 2022, have said they will not run, decisions that could make way for 2028 presidential bids. Representative Kristen McDonald Rivet said last week that she planned to run for re-election.