Former President Donald Trump waded into another battleground Senate race Monday, endorsing former Rep. Mike Rogers, a one-time Trump critic, in Michigan’s crowded Republican primary.

“He will tirelessly fight to Secure the Border, Stop Inflation, Grow the Economy, Strengthen our Military / Veteran Support, and Protect and Defend our always under siege Second Amendment,” Trump wrote in a post on Truth Social. “Mike Rogers will be a Great and Powerful Senator for Michigan, and has my Complete and Total Endorsement.”

Rogers has emerged as a front-runner in the August primary for the seat held by Sen. Debbie Stabenow, a Democrat who is not seeking re-election this year. The National Republican Senatorial Campaign Committee has endorsed Rogers, and his chances improved after former Detroit police chief James Craig dropped out of the GOP race last month.

“Thank you, Mr. President!” Rogers posted on X. “Excited to get to work with you to Get America and Michigan Back on Track!”

A Trump-Rogers alliance would have seemed unlikely a year ago. Rogers, who had been out of politics since 2015, had been exploring a long-shot Republican presidential bid.

“Trump’s time has passed, but we still want to speak to people who are frustrated with where America is going,” Rogers told The Washington Post in November 2022.

And in a January 2023 interview with NBC News, Rogers questioned whether Trumpism was a successful formula for Michigan Republicans after massive midterm losses.

“Remember ‘The Gong Show?’” Rogers asked, referring to a late ‘70s televised talent show where losers were voted off by the sound of a gong. “I think we got a double gong.”

Rogers has praised Trump since launching his Senate campaign and endorsed the former president in January. His competition in the Senate primary features two former congressmen who voted to impeach Trump — Justin Amash and Peter Meijer. Also running are Nikki Snyder, a state Board of Education member, and businessman Sandy Pensler, who lost to Trump-endorsed John James in Michigan’s 2018 GOP Senate primary. James lost to Stabenow that fall, but he won a House seat in 2022.

“The chaotic Senate primary is getting even nastier as Trump pours gasoline on the fire,” Michigan Democratic Party Chair Lavora Barnes said in a statement responding to Trump’s endorsement.

Stabenow’s retirement and Michigan’s swing-status in recent presidential elections is expected to make for a competitive Senate race this fall. Rep. Elissa Slotkin has emerged as the front-runner on the Democratic side.

Trump has endorsed in several other top Senate races this year, including Ohio, where his preferred candidate, Bernie Moreno, is trying to fend off two rivals in that state’s March 19 GOP primary. In Montana, Trump’s endorsement of Tim Sheehy chased Rep. Matt Rosendale out of what was expected to be a nasty Republican primary.