Sen. John Cornyn (R., Texas).

When deciding whether to seek re-election next year, Texas Sen. John Cornyn said one consideration rose above all: A desire to thwart the other Republican hopeful, state Attorney General Ken Paxton.

“I refuse to let someone of his character—or lack of character—represent Texas in the Senate,” Cornyn said in an interview with The Wall Street Journal. “I consider this to be drawing a line in the sand.”

Texans are gearing up for an ugly primary between Cornyn, a two-decade senator arguably associated with the GOP of another era, and Paxton, a MAGA combatant who has prevailed in Texas politics despite repeated accusations of legal and ethical wrongdoing.

Their party is gearing up for a headache.

Republican leaders fear that nominating Paxton, who has an edge with the farthest-right voters active in primaries, could hand Democrats their best opportunity for a win in Texas in decades. A competitive Texas senate race in the general election, they warn, could cost Republicans upward of $250 million, forcing the party to put resources into a red-leaning state that could go elsewhere and potentially threatening their Senate majority.

With that in mind, Senate Majority Leader John Thune (R., S.D.) and Tim Scott (R., S.C.), chair of Senate Republicans’ campaign arm, both asked President Trump to endorse Cornyn before Paxton announced his campaign. Cornyn himself asked, too.

But Trump has so far refused to endorse either Cornyn or Paxton, saying he’s friendly with both men.

“They’re both friends of mine,” Trump said in April. “I’ll make a determination at the right time.”

Texas Attorney General Ken Paxton has an edge with the farthest-right voters active in primaries.

Paxton at a Trump rally in Robstown, Texas, in 2022.

A representative for Paxton’s campaign declined to answer questions. In a statement, the attorney general called Cornyn’s attacks desperate and fake. “This senate race is a test of character, which is why John Cornyn is losing this primary by margins never before seen in modern political history for an incumbent,” the statement said. “He stands for nothing.”

The president has held off on endorsements for several vulnerable Republicans in other states, including Sen. Thom Tillis in North Carolina and Sen. Bill Cassidy in Louisiana.

But the Texas primary has Republicans most worried. Such heavy spending in Texas during next year’s midterms would take resources away from Michigan and Georgia, where Republicans are trying to go on offense to challenge Democrat-held seats, national Republican strategists said. Republicans now hold a 53-47 advantage in the Senate.

Cornyn, a onetime Texas supreme court justice, has a staunchly right-wing voting record but has grappled with the Trump-era perception that he isn’t MAGA enough. He was booed at the state party convention in 2022, after helping negotiate a bipartisan gun safety bill in the wake of the elementary school shooting in Uvalde, Texas. Paxton, who has been helped by Christian oil billionaires, is known for filing dozens of lawsuits against the Biden administration. In 2020, he sought to block the electoral votes of four other states in an effort to overturn the presidential race for Trump.

Waiting in the wings is Rep. Wesley Hunt, a Houston-area congressman who has met with national Republicans and talked to the White House about a possible candidacy. A person familiar with the conversations said Hunt made the case that only he can win both a primary and a general election without draining party coffers.

Cornyn said he would be willing to step aside for the right candidate to defeat Paxton but he doesn’t believe Hunt, who has little name recognition, could win.

Paxton’s political career has withstood numerous claims of misconduct. He was re-elected twice while under indictment on securities fraud charges. (Prosecutors dropped the charges last year in exchange for Paxton paying $271,000 in restitution to the alleged victims.) Eight of his top-ranking deputies reported to the Federal Bureau of Investigation that Paxton was illegally using his office to benefit a donor. (Paxton denied the allegations and they didn’t result in charges.)

In 2023, Paxton became the third official in Texas history to be impeached.

Rep. Wesley Hunt, a Houston-area congressman, has met with national Republicans and talked to the White House about a possible candidacy.

The Republican-majority state House voted to charge him with conspiracy, misapplication of public resources, unfitness for office, bribery and obstruction of justice. (The state Senate acquitted and reinstated him.) Earlier this year, a judge found that Paxton had improperly fired four of the aides who reported him to the FBI and awarded them $6.6 million in damages.

Cornyn has said he intends to make a campaign issue of Paxton’s history, including a property-buying spree he and his wife, a state senator, underwent in the years after the pandemic. The couple now own at least 10 residential properties, most purchased since he was elected attorney general in 2014. Paxton’s required state and federal financial disclosures have at times been late or omitted the properties.

“He just operates as though the rules don’t apply to him,” Cornyn said.

Most recently, documents reviewed by The Wall Street Journal indicate that Paxton and his wife represented on mortgage documents that at least one of the homes they own in the state capital of Austin was their principal residence, even as they lived, voted and held office in the Dallas area from a house on which they receive a homestead tax break. Misrepresenting the Austin property as a principal residence, which typically results in a lower interest rate on the loan, could constitute mortgage fraud, real-estate experts said.

The FBI last month opened a criminal investigation into New York Attorney General Letitia James, following accusations of mortgage fraud, including that she affirmed on a mortgage document that a property in Virginia was her principal residence, even though she was required to live in New York. James has called the probe baseless and politically motivated.

Paxton’s campaign wouldn’t comment on the property.

In Texas, Paxton’s legal problems have only bolstered his reputation among the most conservative Republican base voters. They equate his woes with the indictments Trump faced, said Bobby Eberle, a right-wing commentator and GOP chairman in Fort Bend County, southwest of Houston.

“It’s like, oh, they’re going after Trump and now they’re going after one of our top conservatives,” he said.

Cornyn is behind among primary voters, in some estimates by double digits, according to polls.

Cornyn, meanwhile, has come to be seen as exactly the kind of establishment Washington insider distrusted by the grassroots, Eberle said.

Polls have shown Cornyn behind among primary voters, in some estimates by double digits. One survey in May by Texas Southern University found Paxton leading both Cornyn and Hunt, but with the narrowest margins in hypothetical matchups with Democrats.

A survey earlier in the month by the Senate Leadership Fund showed Cornyn 16 points down in the Republican primary, but Paxton likely to lose to Democrat Colin Allred in the general election. Allred, a Dallas-area former congressman who challenged Sen. Ted Cruz last year, hasn’t said whether he will run for the seat.

One Republican strategist who works on Senate races said panic is starting to set in. Party insiders are comparing the race to Alabama’s 2017 Senate race, when Roy Moore, a jurist with a history of misconduct, prevailed over an establishment-supported candidate in the Republican primary only to lose to Democrat Doug Jones in the general election. Pressure will quickly grow on Cornyn to improve his poll numbers—a challenge, given the cost of advertising in Texas, strategists said.

Write to Elizabeth Findell at [email protected], Lindsay Wise at [email protected] and Mark Maremont at [email protected]