Thirteen candidates are running in the Republican primary for Texas’ 21st Congressional District on March 3, 2026. The filing deadline is December 8, 2025. Two candidates lead in media attention and endorsements: Mark Teixeira (R) and Trey Trainor (R).

Incumbent Chip Roy (R) is running in the Republican primary for Texas Attorney General in 2026. For a list of U.S. Representatives who are not running for re-election in 2026, click here. The last time this district was open was 2018, when Roy was first elected.

According to The Texas Tribune’s Marijke Friedman, “Both Roy and [President Donald] Trump won handily in the 21st District in 2024, and the seat remained solidly Republican under the new congressional map approved by the Texas Legislature.” As of October 2025, The Cook Political Report with Amy Walter, Inside Elections with Nathan Gonzales, and Larry J. Sabato’s Crystal Ball each rated the general election Safe/Solid Republican.

Teixeira is a former professional baseball player and World Series champion. Teixeira says he would support the military, end American involvement in long-term conflicts, and prioritize American interests to “champion President Trump’s America First agenda.” Teixeira says he would support law enforcement and border security to promote local and national safety. He says he would cut federal spending and promote Texas’ oil, gas, and nuclear industries to improve the economy. Teixeira also says he would “restore patriotic education rooted in American and Texas values.” U.S. Reps. Jim Jordan (R-Ohio) and Steve Scalise (R-La.) endorsed Teixeira.

Trainor is a lawyer who previously worked as general counsel for the Texas Secretary of State and the Republican Party of Texas. He also served as a commissioner on the Federal Election Commission (FEC) from 2020 to 2025. Trainor says his legislative priorities would be improving border security, reducing federal spending, and upholding Constitutional rights. Trainor is campaigning on his legal experience, saying he has “been on the front lines defending the Constitution” throughout his career. He is also campaigning on his experience on the FEC, saying he has a history of promoting election security. Highlighting Trump appointing him to the FEC, Trainor says he supports Trump’s policies and describes himself as a “soldier of the conservative cause and the America First agenda.” Texas Railroad Commissioner Wayne Christian (R) and former chair of the Republican Party of Texas Cathie Adams (R) endorsed Trainor.

Also running in the primary are Daniel Betts (R), Jason Cahill (R), Jacques DuBose (R), Ezekiel Enriquez (R), Denis Goulet (R), Weston Martinez (R), Matt Okerson (R), Paul Rojas (R), Kyle Sinclair (R), Heather Tessmer (R), and Mike Wheeler (R).

Texas conducted redistricting between the 2024 and 2026 elections. As a result, district lines in this state changed. To review how redistricting took place in Texas, click here. For a list of all states that drew new district lines between 2024 and 2026, click here.