U.S. Rep. Jasmine Crockett and state Rep. James Talarico both pitched themselves as fighters Saturday during their first, and perhaps only, debate in the Democratic primary for U.S. Senate, with Crockett framing herself as a “street fighter” and Talarico leaning into his record battling GOP proposals in the Texas House.

The leading Democratic candidates for the U.S. Senate seat in Texas made their cases to voters on Saturday in their first head-to-head debate, where the candidates discussed issues like immigration, a...