Washington(CNN) Former House Speaker John Boehner called Republican presidential candidate Ted Cruz "Lucifer in the flesh," in a withering interview at Stanford University published Thursday.
In it, he repeated many of the same attacks he used last month while calling on his successor, Paul Ryan, to seek the Republican nomination.
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"Lucifer in the flesh," Boehner told Stanford's David Kennedy, a history professor emeritus, according to the Stanford Daily. "I have Democrat friends and Republican friends. I get along with almost everyone, but I have never worked with a more miserable son of a bitch in my life."
Boehner also said he was "texting buddies" with GOP presidential front-runner Donald Trump and friends with former House colleague and fellow Ohioan, John Kasich.
The account in the student newspaper is accurate, a source close to Boehner confirmed Thursday.
Cruz tweeted a response Thursday morning: "Tell me again who will stand up to Washington? Trump, who's Boehner's "texting and golfing buddy," or Carly & me?"
He later told reporters Boehner "allowed his inner Trump to come out."
"The interesting thing is I've never worked with John Boehner, I don't know the man," Cruz said. "Indeed, during the government shut down, I reached out to John Boehner, to work with him to get something meaningful done. He said, 'I have no interest in talking to you.' "
Boehner and Cruz clashed over the government shutdown and Obamacare fights from the time Cruz took his Senate seat in 2013 to when Boehner stepped down last fall.
Cruz continued: "When John Boehner calls me Lucifer, he is directing it at you. What Boehner is angry at is me standing with the American people."
Cruz has been arguing for months now that he is the candidate best positioned to unify the Republican Party ahead of the November battle. But his support among his many Senate and House colleagues has been tepid at best -- with a handful of senators only recently endorsing him.
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Boehner's relationship with Cruz pre-dates their time in Congress together. Cruz was hired as part of Boehner's legal team, after he sued a Democratic congressman, Rep. Jim McDermott of Washington state, for breaking wiretapping laws back in 1998.
The Ohio congressman was caught on a telephone phone call talking to then-House Speaker Newt Gingrich about ethics allegations against the speaker, and McDermott released the tape to the press. After years of litigation of arguing the release of the call by McDermott was unlawful, Boehner prevailed in the case.
Boehner also compared Cruz to the devil last month in a talk before financial industry lobbyists and executives in Florida. In the same March speech he urged Ryan to seek the nomination.
"If we don't have a nominee who can win on the first ballot, I'm for none of the above," Boehner said at the Futures Industry Association conference. "They all had a chance to win. None of them won. So I'm for none of the above. I'm for Paul Ryan to be our nominee."
Ryan has adamantly ruled out accepting the Republican nomination. He also said Thursday he has "a much better relationship with Sen. Cruz" than Boehner.
"Look, my job is to help unify our party. It's to take all pieces of the conservative movement in the Republican Party and help stitch them together, especially after a primary," Ryan said at a news conference. "I have a very good relationship with both of these men and I'm going to keep it that way."