The significant defeat of Senator John Cornyn of Texas in a primary runoff highlighted a shift among Republican voters. Once staunch party figures, they have now embraced President Trump’s preferences over the past decade.
Mr. Trump’s loyal base continues to participate actively in Republican primaries. This support enables him to remove incumbents like Mr. Cornyn, whom he considers disloyal. Despite a decline in his overall popularity, Mr. Trump has maintained a series of primary victories. This situation may create a favorable midterm environment for Democrats.
Mr. Cornyn, who has held office for four terms and was once a key Republican senator, lost significantly to MAGA-aligned challenger Ken Paxton. Mr. Paxton won by almost 28 percentage points. This loss occurred despite Mr. Paxton being outspent in what became the most expensive Senate primary contest in recent history. According to Decision Desk HQ, this was the worst result for a sitting senator in a two-person primary or runoff since 1974.
Mr. Cornyn’s defeat followed another significant loss. Senator Bill Cassidy of Louisiana, also opposed by Mr. Trump, failed to advance to the runoff in his re-election campaign. He finished with less than 25 percent of the vote in a four-candidate race.
The decisive primary losses of the two senators underscore the gap between the GOP base — particularly primary voters — and any GOP leader outside of Trump.
Moreover, Mr. Trump played a role in the defeat of Representative Thomas Massie of Kentucky in a House primary on May 19. “It’s not easy beating incumbents,” Mr. Trump remarked earlier that day.