Mark Teixeira is trading the batter’s box for the ballot box -- and his first big political test is already in the books. The former MLB slugger won the Republican primary for Texas’ 21st congressional district Tuesday night ... securing more than 61% of the vote in a crowded 12-candidate field and avoiding a runoff. “This is a huge victory, and I’m truly honored to have such strong support from the people of TX-21,” Teixeira posted on X . “Thank you! I’m so grateful to everyone who voted, put