Rep. Mike Gallagher (R-Wisc.) announced Saturday that he will not seek reelection this fall after four terms in office.

Gallagher, the chair of the Select Committee on the Chinese Communist Party, released a statement via social media where he said when he ran for office eight years ago, he “promised to treat my time in office as a high-intensity deployment.”

He served seven years in the U.S. Marines before running for Congress. Gallagher said through his time on the Armed Services and Intelligence Committee, he has “accomplished more on this deployment than I could have ever imagined.”

“But the Framers intended citizens to serve in Congress for a season and then return to their private lives. Electoral politics was never supposed to be a career and, trust me, Congress is no place to grow old,” his statement said. “And so, with a heavy heart, I have decided not to run for re-election.”

Gallagher was one of three Republican members in the House who went against their party this week, voting against the impeachment of Homeland Security Secretary Alejandro Mayorkas and tanking the bill. He refused to reveal his stance against the impeachment all day but ultimately cast his vote against the effort on Tuesday.

On the House floor, top GOP lawmakers swarmed the Wisconsin lawmaker in what appeared to be an effort to convict him to change his vote. In an op-ed, he argued that impeaching Mayorkas would have “opened Pandora’s box.”

A day later, a GOP consultant, Alex Bruesewitz, who is aligned with former President Trump, weighed running against Gallagher for Wisconsin’s 8^th District. A source confirmed to The Hill that Bruesewitz had “a ton” of interest from members of Congress and the “Trump orbit” about challenging Gallagher after he voted against the Mayorkas impeachment.

In his statement, Gallagher thanked “the good people of Northeast Wisconsin for the honor of a lifetime.” He said the four terms he served in Congress strengthened his conviction that “America is the greatest country in the history of the world.”

“And though my title may change, my mission will always remain the same: deter America’s enemies and defend the Constitution,” he concluded.

Gallagher joins a growing list of GOP and Democratic members in the House who are not seeking reelection. According to Cook Political Report, his district is a solidly Republican district.