Rep. Mark Green steps down from Congress, resulting in a tighter Republican majority for Speaker Johnson in the House.

House Homeland Security Committee Chair Mark Green (R-Tenn.) speaks alongside House Speaker Mike Johnson (R-La.) after the House passed budget reconciliation legislation at the U.S. Capitol on May 22, 2025. Francis Chung | POLITICO via AP Images

Rep. Mark Green, R-Tenn., announced his official resignation from Congress on Friday, a move that was anticipated but could, at least for now, reduce Republicans’ already narrow majority in the House. “To my constituents across Tennessee’s 7th District—thank you. The trust you put in me is humbling. I will look back fondly on my years of serving as your voice in Washington,” Green wrote in a post on X.

With his resignation, Republicans are down to a 219-212 majority in the House, at least until his seat in the solidly red district is filled. His resignation will be effective July 20, according to a letter Green sent to House Republican leadership.

Green’s resignation poses a challenge to House Speaker Mike Johnson’s already narrow majority in the lower chamber, which was evident this week as he sought to advance President Donald Trump’s “big, beautiful bill.” Johnson struggled to unify his conference around the megabill, and the slim majority left little room for defections. With Green’s departure, Johnson could face an even more difficult path ahead.

Green, who chairs the Homeland Security Committee, stated that he is returning to the private sector to start his own business, though he did not provide specific details. “While I cannot give the details here, I will be doing something specifically designed to help America compete against the CCP [Chinese Communist Party], but this time in business,” Green said in a video on X.

Elected to Congress in 2018, Green succeeded Sen. Marsha Blackburn. While his retirement has been expected—he mentioned in June that he was stepping away from his role—it comes amid notable turnover in Congress, including Rep. Mike Waltz, R-Fla., who left his post to serve in the Trump administration before resigning from that role. Another Republican, Rep. Don Bacon, a centrist, also recently announced his retirement from Congress, creating an opportunity for Democrats to potentially win the House seat representing Bacon’s Omaha, Nebraska, district.