In a statement, Gallagher, 39, invoked the framers of the Constitution who “intended citizens to serve in Congress for a season and then return to their private lives.”

Gallagher, who has advocated for term limits in Congress, said that, “Electoral politics was never supposed to be a career and, trust me, Congress is no place to grow old. And so, with a heavy heart, I have decided not to run for reelection.”

Gallagher’s departure gives Republicans just months to join the race before the state’s primaries. Alex Bruesewitz, a Trump ally with ties to Gallagher’s safely Republican district, had expressed a desire to run against Gallagher after his vote on Mayorkas.

Gallagher, a former Marine Corps intelligence officer who deployed twice to Iraq, had served as the Chairman of the House Armed Services Subcommittee on Cyber, Information Technologies, and Innovation and on the Permanent Select Committee on Intelligence. He was the youngest chair of a select committee in the modern era, according to his office.

The Green Bay Republican had established himself as one of Capitol Hill’s top national security and foreign policy hawks. He was generally viewed as a moderate member of his conference, and a rising star. Gallagher’s decision is the latest in a spate of House retirements in both parties, but especially among Republicans.

“Eight years ago, when I first ran for Congress, I promised to treat my time in office as a high-intensity deployment,” Gallagher said in a statement. “We’ve accomplished more on this deployment than I could have ever imagined.”

Along with Sen. Marco Rubio (R-Fla.), Gallagher called for banning TikTok in the U.S. and had traveled to Taiwan, returning to urge his fellow lawmakers to arm Taiwan robustly in the face of a potential Chinese invasion.

Gallagher, who declined a request to be interviewed, told the Milwaukee Journal Sentinel that he plans to enter the private sector and spend more time with his young family, which he hoped to expand. He told the news outlet that his future work will focus on defense policy, in line with his long-standing national security goals.

Gallagher had not telegraphed how he would vote on the Mayorkas’s impeachment, he was swarmed on the House floor by his colleagues, who engaged in an apparent last-ditch attempt to change his mind.

Rep. Marjorie Taylor Greene (R-Ga.), who has tried multiple times to force the House to expedite impeaching Mayorkas, was seen shouting at Gallagher, alongside Tennessee’s Mark Green, the chairman of the Homeland Security Committee who spearheaded the investigation into Mayorkas. Rep. Jodey Arrington (R-Tex.), a close ally of Speaker Mike Johnson’s (R-La.), then animatedly tried to persuade Gallagher to flip his vote as Rep. Dusty Johnson (R-S.D.) listened in, The Washington Post reported.

Gallagher told the Journal Sentinel that his decision to leave Congress had nothing to do with his controversial vote on Mayorkas, that he was stepping away for personal reasons and because he never saw the position as a long-term appointment.

During his time in office, Gallagher had occasionally broken with former president Donald Trump, as he did when he called the former president to call off his supporters as they stormed the U.S. Capitol on Jan. 6, 2021. He was critical of the insurrection, but ultimately voted against impeaching Trump.

The primary for the U.S. House race in Wisconsin is not until Aug. 13, and the filing deadline is June 3.