Democratic U.S. congressional candidate Jessica Cisneros (TX-28) speaks alongside her family during a watch party on March 01, 2022, in Laredo, Texas. Late results hint that Cisneros and U.S. Rep. Henry Cuellar (D-TX) could face a primary runoff with neither getting more than the 50 percent necessary for an outright win.Getty Images

Cisneros, Rep. Cuellar Head to Runoff in Texas

· 5 NBCDFW

Democratic challenger Jessica Cisneros, a 28-year-old immigration attorney running for Congress with heavy support from progressives, has forced a primary runoff against U.S. Rep. Henry Cuellar in South Texas.

Neither candidate Tuesday night got more than 50% of the vote needed to win outright.

The race was among the most heated in Texas’ first-in-the-nation primary. Cuellar is among the most conservative Democrats in Congress, and a Cisneros victory would bring a seismic liberal shift to the district that runs from San Antonio to the Texas border.

Cisneros is a former intern of Cuellar’s who also ran against him in 2020. She narrowly lost, and this time ran a more aggressive campaign that attacked Cuellar over FBI agents searching his home just before voting began.

The Associated Press has learned that the investigation relates to the former Soviet Republic of Azerbaijan. Cuellar has not been charged with a crime and has denied wrongdoing.

The runoff is in May.