U.S. Sen. Susan Collins has criticized President Donald Trump’s decision to endorse a candidate whom she called “ethically challenged” in the Texas U.S. Senate primary.

On Tuesday, Trump endorsed Texas Attorney General Ken Paxton, who will take on incumbent Sen. John Cornyn in next week’s Republican primary.

Paxton was impeached in 2023 on allegations that included bribery and obstruction of justice. He was acquitted, however, by the Texas Senate. His wife has also accused him of extramarital affairs, filing for divorce last year on “biblical grounds.”

Trump’s endorsement reportedly angered several Republicans on Capitol Hill, including Collins.

“I don’t understand it,” Collins told reporters. “He is an ethically challenged individual. John Cornyn is an outstanding senator and deserved, in my judgment, the president’s support. Obviously it’s the president’s call, but I’m disappointed that he did it.”

Collins’ comments risk reigniting the rhetorical wrath of Trump as she faces a tough reelection battle this fall.

Collins has never supported Trump as a candidate and voted to impeach him after the Jan. 6, 2021, riots at the Capitol Building. She breaks with her party’s standard-bearer at the third highest rate among Senate Republicans, though she has voted with him 95% of the time.

Trump has taken aim at Collins over the years. In 2022, he called Collins “absolutely atrocious” after The New York Times reported that she and then Senate Majority Leader Mitch McConnell, R-Ky., were recruiting anti-Trump candidates.

A month lather, Trump called her “wacky” for pushing to make it harder for members of Congress to challenge election results — changes sought after Trump pressured former Vice President Mike Pence to overturn the 2020 election results.

Earlier this year, Trump placed Collins in a group of Republicans who “should never be elected to office again” after the lawmakers voted to rein in his military campaign in Venezuela.

But their relationship recently showed signs of improvement — at least publicly — ahead of the midterm elections. Collins is the only Republican senator running this fall in a state won by Democrats in the 2024 presidential election.

In February, Trump praised Collins’ leadership of the budget committee during a White House signing ceremony, as she stood nearby clutching a red “Make American Great Again” hat.

And a month later, he told Fox News that “I hope she wins,” while also admitting he doesn’t really like her much.

Last week, Vice President JD Vance defended Collins’ record during an antifraud rally in Bangor.

“I get frustrated with Susan Collins,” Vance said. “I wish that she was more partisan, but the thing I love about Susan is she is independent because Maine is an independent state, and frankly, if she was as partisan as I sometimes wish that she was, she would not be a good fit for the people of Maine.”