Former GOP Rep. Peter Meijer announced Monday that he would run for Senate in Michigan, joining a crowded field of contenders in the competitive open seat race.

“I am excited to join the race for the United States Senate!” Meijer posted on X, accompanying a statement announcing his campaign.

“We considered every aspect of the campaign, and are confident we have the best chance of taking back this seat for the Republicans and fighting hard for a conservative future,” he wrote in the statement.

Meijer was one of just 10 House Republicans who voted to impeach former President Donald Trump after the January 6, 2021, riot and he subsequently lost narrowly to a Trump-endorsed primary challenger in the 2022 midterms. Republicans went on to lose his battleground seat in Michigan’s 3rd Congressional District, now held by Democratic Rep. Hillary Scholten.

He enters an increasingly crowded field of candidates vying to replace Democratic Sen. Debbie Stabenow, whose decision to retire set off an open seat race in one of the top battleground states of recent election cycles.

In the Republican primary, he’ll face former Michigan Rep. Mike Rogers, former Detroit Police chief James Craig, who was disqualified as a gubernatorial candidate in 2022, and Michigan State Board of Education member Nikki Snyder, among others.

The Senate Republican campaign arm, which is backing Rogers in the race, privately urged Meijer to sit out of the race, according to a source familiar with the matter. The fear is that Meijer could split the primary vote among moderate Republicans and hand the GOP nomination to Craig, a conservative candidate that the campaign arm fears would take the state off the map in 2024.

Meanwhile, Democratic Rep. Elissa Slotkin’s decision to run gives Democrats a prominent and battle-tested candidate, while actor Harper Hill has also joined the race.