Republican Rep. Tony Gonzales is headed to a runoff election after failing to win more than 50 percent of the vote in the Republican primary for Texas’ 23rd Congressional District, a race overshadowed in recent weeks by allegations involving a former staff member.

Gonzales, who has represented the sprawling southwest Texas district since 2021, fell short of the threshold needed to avoid a runoff in Tuesday’s four-candidate GOP primary. The district is rated R+7 by the Cook Political Report, meaning the Republican nominee is generally favored in the general election.

The incumbent will now face a May runoff against Brandon Herrera, a conservative influencer who narrowly lost to Gonzales in the 2024 Republican primary by fewer than 400 votes. Herrera is backed by the campaign arm of the House Freedom Caucus.

The primary contest has been dominated by allegations that Gonzales had an affair with a married staff member who later died after setting herself on fire near her home in September 2025. Gonzales, a married father of six, has strongly denied wrongdoing and accused the late staffer’s husband of attempting to blackmail him.

“During my six years in Congress, not a single formal complaint has been levied against my office,” Gonzales wrote on social media earlier this year, arguing the accusations surfaced shortly before the election as part of what he described as coordinated political attacks.

Despite the denial, the controversy sparked criticism from some fellow Republicans in Congress. Several lawmakers publicly called on Gonzales to resign.

Rep. Eli Crane said he had already endorsed Herrera in the race and criticized the allegations as inappropriate behavior for someone in a position of authority.

Rep. Mark Harris described the allegations as “extremely concerning."

Rep. Nancy Mace has also called on Gonzales to resign and recently pushed for a House vote requiring the House Ethics Committee to release more information about lawmakers accused of sexually harassing staff.

The runoff election will determine the Republican nominee for the district, which stretches across a large portion of southwest Texas along the U.S.-Mexico border. Because the seat typically favors Republicans, the outcome of the GOP runoff could play a decisive role in determining who represents the district in Congress next year.