SCHERTZ, Texas — In a last-minute appeal to voters, Senator John Cornyn criticized his opponent, Texas Attorney General Ken Paxton, for what he described as a “vanity project” in the Senate Republican primary. According to Cornyn, Paxton’s campaign could jeopardize Republican success in the midterm elections and heighten the risk of a third impeachment for President Trump.

Addressing supporters at a civic center near San Antonio on the eve of the Texas primary elections, Cornyn (R-Texas) cautioned against Republican complacency. He emphasized the importance of preventing Democrats from winning a statewide congressional office—something they haven’t achieved since 1994.

“Ken Paxton is on a personal crusade,” Cornyn asserted to the crowd. “He’s not considering the repercussions for the Republican Party or the down-ballot races. But rest assured, President Trump is concerned. He’s warned that losing the House could lead to another impeachment,” Cornyn added, referencing Trump’s own words.

Cornyn expressed his disappointment at the situation, reminding the audience of his previous victory over Democrat M.J. Hegar, which he secured by a ten-point margin.

“I believe I can contribute once more,” Cornyn continued. “I can assist President Trump in maintaining our Senate seat, and we aim to elect five new congressmen from the newly established districts. All of this hangs in the balance.”

Following the event, John Lujan, a Texas state representative campaigning in the newly created 35th Congressional District, shared his thoughts with The Post. “Senator Cornyn draws in a strong base of Republicans, both from the right and the center,” Lujan remarked. “Having him lead the ticket would be crucial.”

House Democrats have already filed articles of impeachment against the 47th president — but are expected to pursue a more serious inquiry if they succeed in flipping the House this November.

Paxton is currently leading Cornyn in the primary fight, 40% to 36.3%, according to the RealClearPolitics polling aggregator, with Rep. Wesley Hunt (R-Texas), who entered the race last September, in a distant third place at 15.5%.

Trump has declined to endorse any of the three candidates, and it’s unclear whether he would tip the scales in a runoff race.

That all but ensures the Texas AG and Republican senator — whose allies have been running attack ads against Hunt in the final weeks of the primary contest — will head to a runoff election, given no candidate has cracked the 50% threshold.

Paxton, a conservative firebrand, and Cornyn, a moderate, have also launched direct attacks on each other in the race’s final days.

Cornyn and his allies have focused on Paxton’s infidelity that led to his impeachment in the Texas House — and divorce from his wife — while the state attorney general’s team has needled the senator with an AI-generated campaign ad of him being Rep. Jasmine Crockett’s dance partner in the Senate.

The Post spoke with half a dozen voters in Texas who attended Trump’s event in Corpus Christi on Friday — and they said they opposed “RINOs” like Cornyn and casting their ballot for Paxton.

On Monday, Cornyn slammed the theatrics, telling voters in attendance: “We don’t need any more performance artists.”

“They want to get on TV. They want to say outrageous things and get a lot of attention, and then they wanna get the most clicks on social media, and then they want to raise money — and call it a day,” he explained. “Well, that’s not my definition of public service.”

“Unfortunately, our attorney general doesn’t believe that character still matters,” he also said. “I believe that character is on the ballot and after a scandal-plagued career, he thinks he can still get away with it and that people don’t care.”

Robert Castenada, a longtime Cornyn supporter who attended Monday’s event, rattled off his reasons for voting against Paxton, telling The Post: “He’s been going through a divorce. He’s had the lawsuits against him. He got impeached.”

By contrast, Castenada said, “Senator Cornyn has been just been a workhorse,” highlighting how he’s “known him for over 40 years ” and recalled having first voted for the Republican when he was a district judge in Bexar County.

Paxton’s daughter Mattie Hayworth responded to her father’s critics in a column last week that declared: “My dad is not perfect; none of us are. But he is a man of deep faith, genuine love for his family, and an unrelenting commitment to doing right by the people of Texas.”

Billie Langhus, another attendee, added, “I would not vote for Ken Paxton because I think he’s rather weak on city issues and state issues, so why would I want him in the Senate?”

“I’m a retired San Antonio firefighter, and I was on the legislative committee … and when we went to our tour in Washington, DC, … we had meetings with just Democrats,” Lujan explained. “And they said, ‘Republicans won’t meet with us.’”

But Cornyn did.

“He’s always been open to us. He’s always listened to us, and from that point on we started endorsing, as a firefighters group, Senator Cornyn because of the things that he did for public safety,” Lujan said.

At Friday’s event touting “American Energy Dominance,” Trump continued to stay out of the race.

“We have a great attorney general, Ken Paxton,” the president said. “We have a great senator, John Cornyn. They’re in a little race together. … They’re both great people, too.”