Pensler made the announcement at Donald Trump's rally in Grand Rapids on Saturday after being called onto to stage by the former president. Trump endorsed Rogers earlier this year and many in the party have begun to coalesce around Rogers, who served in the U.S. House for 14 years and chaired the House Intelligence Committee.

"We need control of the Senate," Pensler said on stage. "A divisive continued primary effort hurts the chances of that."

"President Trump endorsed Mike Rogers," he added. "Tonight, so am I."

Pensler was seen as a long-shot candidate, having previously lost the GOP primary for Senate in 2018 by over 9 percentage points to now-U.S. Rep. John James, who would go on to lose to incumbent Democratic Sen. Debbie Stabenow.

Stabenow announced that she would retire next year, opening up one of the most competitive seats in the nation.

With Pensler dropping his bid, Rogers' only remaining high-profile opponent is Justin Amash, a former U.S. representative who left the GOP in 2019 after calling for the impeachment of Trump, who was president at the time. Amash represented Grand Rapids from 2011 to 2021.

Democrats have coalesced around Rep. Elissa Slotkin as their candidate. She faces actor Hill Harper in the Aug. 6 primary but has a massive cash advantage.

National Republicans had hoped Rogers would have a similarly easy path to his party's nomination. But the campaigns of former U.S. Reps. Amash and Peter Meijer, who ended his bid earlier this year, made his task a little more complicated.

Trump's endorsement in March of Rogers - who in the past had been critical of Trump before changing his tune on the Senate trail - has pushed many other GOP candidates out of the race.

Despite the turmoil within the Democratic Party regarding their top of the ticket, the party hasn't lost a Senate race since 1994 and has exceeded expectations in recent Michigan elections.