Sen. John Fetterman’s (D-Pa.) new memoir details a souring relationship between him and Pennsylvania Gov. Josh Shapiro (D), particularly over the governor’s approach to criminal justice.

In “Unfettered,” Fetterman described an “ugliness between us — from which we have never recovered,” Axios reported. He said he saw Shapiro as someone with “political ambition” who sought to ascend to higher office and supported his run for attorney general.

“I was hoping Shapiro would endorse me, given what I had done for him,” Fetterman wrote about his run for lieutenant governor. “He did not.”

Fetterman wrote that in 2019, he voted to pardon brothers Dennis and Lee Horton, both in prison for 30 years for a robbery and a fatal shooting that they deny being involved in. Shapiro voted against the Hortons being pardoned. Fetterman suspected that “what was influencing him was not mere caution but political ambition,” and that “hesitancy was more a matter of optics and fear.”

“I truly believed with all my heart that nobody I ever supported for a pardon was a danger to society,” Fetterman wrote, “and I was willing to stake my political career on it.”

DC Bureau: 50 Year Mortgages Proposed

Shapiro’s vote angered Fetterman enough that he called him a “f—ing a–hole” on a hot microphone. But, as the senator wrote, he believed that “Shapiro did what he felt was right.”

Shapiro is seen as a possible contender for the 2028 Democratic presidential primary. He was floated as a potential running mate for former Vice President Kamala Harris in 2024 before she chose Minnesota Gov. Tim Walz (D).