U.S. Sen. John Cornyn (R-Texas) spent the last day before his high-profile primary race traversing Bexar County, first a rally at USAA’s Northside campus, then a fundraiser at Club Giraud, bookended by another rally at the Schertz Civic Center.

In 24 years in the U.S. Senate, Cornyn has seen many of his colleagues fall to primary challengers they didn’t take seriously enough.

Now a man who’s spent a career preaching primary proactivity is on the brink of his own potential upset — despite a campaign that’s done everything thing it could to ward it off.

He hired up conservative campaign staff at the beginning of the cycle, had spent nearly $70 million on his reelection race so far, and yet still trails Attorney General Ken Paxton in most of the recent public polls.

Speaking to the gathering in Schertz, Cornyn said Tuesday’s primary election was only the beginning.

An eight-candidate race is likely headed to a runoff between Cornyn and Paxton for the GOP nomination, and Cornyn said he believes he can turn it around even if he doesn’t finish first this round.

“We’ve got three of us in the primary now, and you ain’t seen nothing yet,” Cornyn said, referring to himself, Paxton and another primary opponent, U.S. Rep. Wesley Hunt (R-Houston), who has also been spending money. “I’ll be able to give the Attorney General my full and undivided attention, and he’ll be receiving that.”

An old pro

Cornyn has much experience from twice chairing the GOP’s Senate campaign arm — a role that involves raising money across the country, helping determine the party’s strongest candidates and directing spending accordingly.

From his perspective, he said Monday, most upsets happen when lawmakers take their eyes off the ball.

“Senators only run every six years, there’s a lot of change that occurs,” he said.

But efforts to head that off now have candidates like Cornyn in a pickle.

He’s long believed in ensuring the GOP keeps up with the times, investing big in making inroads with Hispanic voters and preparing for a world where Texas could be competitive in November.

“I’m proud of the decades that [my wife] Sandy and I have committed to helping build the Republican Party in this state. We haven’t elected a Democrat statewide since 1994,” he said.

Republican supporters listen as Sen. John Cornyn speaks during a reelection campaign event in Schertz on Monday, March 2, 2026. Credit: Amber Esparza / San Antonio Report

But the result has been a Republican Party so strong that it no longer considers the general election a threat.

GOP primary voters’ biggest litmus test is now loyalty to President Donald Trump — at a time when backlash to the President’s policies could put the state as a whole in play.

“President Trump is now the dominant figure in Republican primary politics, and people want to know, are you willing to support the president and his policies?” Cornyn said. “I have, as you may have seen, 99.3% of the time. But these are unusual times.”

The case for electability

It’s unclear whether either Cornyn or Paxton would put Texas in jeopardy of falling to a Democrat in 2026, but Cornyn spent his 30-minute speech Monday making the case for electability.

Of his 20 political campaigns, he said, his first race was for a district judgeship in Bexar County, where Republicans and Democrats were once swept in and out with the top of the ticket.

“I know what it means to have somebody at the top of the ballot who can help,” he said. “When I talk to my friends like [state Rep.] John Lujan (R-San Antonio) and others who are running in congressional seats, they sure want somebody at the top of the ballot that will not be a dead weight around their neck, but will help.”

Sen. John Cornyn is greeted by State Rep. John Lujan as he arrives for a reelection campaign event in Schertz on Monday, March 2, 2026. Credit: Amber Esparza / San Antonio Report

He also leaned on guest speakers, like 26-year-old Sabinal Mayor Erik Gomez, who made the case for Republicans to keep a senator young leaders can respect — as opposed to Paxton, whose career has been marred by legal troubles.

Cornyn’s long record of service has indeed built much loyalty among party faithful.

Lujan recalled Cornyn taking a meeting with him in D.C. many years ago while Lujan was on the government affairs team for the San Antonio Professional Firefighters’ Union. Lujan was among many local officials in the audience Monday, and his parents even posed for photos with Cornyn.

But to others, Cornyn’s efforts to keep pace with a rapidly shifting GOP have become unforgivable in the era of Trump.

Though Cornyn was once a moderate Republican who sought to satisfy the conservative base with goofy campaign ads in a cowboy hat, state Sen. Roland Gutierrez (D-San Antonio) said the senator has since given up any political independence in a party that won’t allow any daylight from the President.

Speaking at a rally for Democratic U.S. Senate candidate James Talarico on Sunday, Gutierrez said the Republicans’ primary had come down to two options.

“One I used to know and thought was a good man, that was Cornyn, and now I think he’s just a liar and very much confused,” he said, arguing for a change. “But that other son of a b—-, he sure is evil. And I know what’s going to happen on Tuesday. I know that on Tuesday that matchup on the other side is going to be Ken Paxton.”