U.S. Rep. Mac Thornberry is out after a congressional career that has spanned over twenty years.

On Monday, Thornberry, a Clarendon Republican, announced that he would be retiring from the U.S. House of Representatives after first being elected in 1994. Thornberry’s retirement for the 2020 elections means that Texas’ 13th Congressional District will be one of a number of districts with contests for open seats in 2020. Thornberry is ranking member of the House Armed Services Committee and previously served as the committee’s chairman.

Thornberry was most recently re-elected in 2018, defeating Democrat Greg Sagan and Libertarian Calvin DeWeese with 82 percent of the vote. Sagan is also running for Thornberry’s seat again in 2020, and issued a statement on Monday thanking Thornberry for his service to the district, while also saying he looks forward to facing the Republican candidate in the next election.

A successor for Thornberry will be decided in the upcoming 2020 general election.