The Senate GOP primary runoff in Texas is suddenly shaping up to be a wipeout, according to prediction markets, as Republican voters prepare to choose Tuesday who will face Democrat James Talarico in November.
In what was once a toss-up Senate primary race, Texas Attorney General Ken Paxton and Sen. John Cornyn battled for an endorsement from President Donald Trump. Paxton won that fight, and the shift in markets quickly followed suit.
As of Sunday afternoon, Paxton led incumbent John Cornyn by nearly 90% on the online prediction market Kalshi. And on Polymarket, Paxton had a 96% chance of winning Tuesday’s election.
Just days earlier, on May 18, Kalshi had Paxton with a 63.7% chance of winning the nomination and Cornyn at 37.2%.
Trump’s endorsement came on May 19. And by the next morning, the market had completely split. Paxton surged to 90.1%, with Cornyn at 10.3%. Texas Republican primary runoff polling also showed Paxton surging ahead of Cornyn in the days immediately following Trump’s endorsement.








