KVIG Informative

Today Texas Republicans choose between John Cornyn, a 22-year Senate incumbent, and Ken Paxton, the attorney general Trump endorsed to replace him. The race is the most consequential GOP Senate primary of the 2026 cycle. Whoever wins will almost certainly become Texas’s next senator. What the race decides is what kind of Republican Party controls that seat.

Voters in Texas are casting ballots today in a Republican primary runoff that has become a test of Trump’s grip on the party establishment. On one side is Senator John Cornyn, a 22-year incumbent who has served in Senate leadership and is viewed by national Republicans as one of their most reliable institutionalists. On the other is Ken Paxton, the three-term attorney general who survived a bipartisan impeachment with Trump’s backing and has spent his campaign framing Cornyn as part of the D.C. establishment the president ran against.

The race went to a runoff after neither candidate cleared 50 percent in the March 3 primary. Cornyn led narrowly, 43 percent to 41 percent, with the remaining vote split between Congressman Wesley Hunt and minor candidates. Trump endorsed Paxton on May 19, one week before the runoff, calling him a fighter and signaling that Cornyn’s long record of Senate dealmaking placed him on the wrong side of the America First divide.

The $100 million spent in the race makes it one of the most expensive Republican primaries in Texas history. Cornyn has argued that his seniority and relationships in the Senate make him irreplaceable in protecting Texas’s interests, and that Paxton’s legal baggage — a federal securities fraud indictment that has hung over him since 2015, and the impeachment proceedings that ended in acquittal — make him a liability in a general election. Paxton has countered that Cornyn called Trump’s border wall naive, broke with the president on key votes, and represents exactly the kind of go-along institutional Republican that the MAGA movement exists to replace.

National Republicans are divided. Senate Republican leadership, which operates most effectively with Cornyn-style institutionalists, has quietly backed the incumbent. Trump’s endorsement of Paxton puts him in direct tension with his own Senate caucus. The president has already successfully pushed out several Republican incumbents and dissenters in the 2026 cycle, including Senator Bill Cassidy of Louisiana and Representative Thomas Massie of Kentucky. A Paxton win today would extend that pattern into the Senate’s most powerful figures.

The general election implications are real but limited. Texas has not elected a Democrat to statewide office since 1994, and the Democratic candidate for the seat — whichever emerges from a contested primary of their own — faces a structural disadvantage in November regardless of who the Republican nominee is. What the runoff decides is not whether Texas sends a Republican to the Senate. It decides whether that Republican is a negotiator or a disruptor, a deal-cutter or a fighter, a man who has spent two decades building relationships in the institution or a man who has spent a decade building a brand by attacking it.

Polls at the time of publication show Paxton with a lead in the low single digits, within the margin of error of most surveys. Turnout in a late May runoff is historically low, which tends to favor the candidate with the most motivated base. Paxton’s base, energized by the Trump endorsement and by the same voter sentiment that drove the March primary, may have the edge in a low-turnout environment. Results are expected Tuesday evening.