In the first round of the Republican U.S. Senate primary in Texas on March 3, John Cornyn, the incumbent, prevailed over his closest competitor, outgoing Texas Attorney General Ken Paxton, by about two points. But in the second round on Tuesday, Paxton trounced Cornyn, winning 64 percent of the vote in the head-to-head match.
Since the candidates disqualified in the first round received less than 17 percent of the vote in total, that is a pretty striking reversal. The only factor that can plausibly explain it is President Donald Trump's last-minute endorsement of Paxton, which he announced one week before Texans cast their ballots.
