As Texas Republicans prepare for a U.S. Senate primary brawl, Democrats see an opportunity to end a three-decade losing streak. Why it matters: Democrats haven't won a statewide office since 1994, but Republicans' vulnerability — exposed by state Attorney General Ken Paxton's primary challenge against Sen.

Allred is the first major Democrat to announce candidacy for the seat held by Cornyn. Several others have indicated interest, including Beto O’Rourke.

Former Texas Rep. Colin Allred is running for Senate again, this time against Republican John Cornyn, who faces a tough primary challenge, too.