Rep. Mac Thornberry (R-TX) announced his retirement on Monday, making him the sixth House Republican in Texas to retire ahead of the 2020 national election. Thornberry, a 13-term lawmaker who has served in the House since 1995, said he is not seeking re-election but will serve the remainder of his term. “It has been a great honor to serve the people of the 13th District of Texas as their congressman for the last 25 years... We are reminded, however, that ‘for everything there is a season,’ and I believe that the time has come for a change,” the lawmaker wrote in a statement released Monday. Thornberry is the top Republican on the Armed Services Committee. Last year, he became the highest-ranking congressional Republican to declare that the Trump administration should have implemented mandatory sanctions against Russia. “Our nation faces many difficult challenges,” he wrote on Monday. “And none of us can relax our efforts to meet and overcome them, whether at home or around the world.”