Former Major League Baseball star Mark Teixeira announced on Thursday that he will seek the Republican nomination for Texas’s 21st Congressional District, a strongly conservative seat that stretches from suburban San Antonio to the outskirts of Austin. The seat is opening after three-term incumbent Chip Roy said he will run for state attorney general. Teixeira, 45, framed his first run for public office around former President Donald Trump’s “America First” platform, saying he is “ready to help defend Texas families and individual liberty.” The three-time All-Star and 2009 World Series champion with the New York Yankees retired in 2016 after a 14-season career that produced 409 home runs and five Gold Gloves. He and his family returned to Texas in 2021. The ex-slugger enters a GOP primary scheduled for March 3, 2026, that already includes former Travis County district attorney candidate Daniel Betts. Three Democrats and an independent have filed on the other side of the ballot ahead of the December 2025 candidate deadline. The Hill Country district favored Trump by more than 21 percentage points in 2024, making the Republican primary the critical contest.