WASHINGTON (CNN) — Bill and Hillary Clinton rarely talk about their relationship with one another. But in an interview set to air Sunday on CNN’s “State of the Union,” the former president opened up about the woman he said he trusts with his life.

“Whenever I had trouble, she was a rock in our family,” Clinton said during an emotional interview with CNN’s Jake Tapper in Denver.

“I trust her with my life, and have on more than one occasion,” he said, describing his wife as someone who helped him through some of the most trying times of his life.

Bill Clinton described how his wife helped him through years “plagued with self-doubt” in his late 20s and offered him someone to not only lean on, but to help guide him through perilous moments in his career.

“I was the youngest former governor in American history in 1980 on election night. I got killed in the Reagan landslide,” Clinton remembered. “People I had appointed to office would walk across the street, they were so afraid of the new regime in Arkansas, and would not shake hands with me. My career prospects were not particularly bright.”

“And she never blinked. She just said, ‘Hey. It’ll turn around. I believe in you. You’ve got this,'” he said.

Close friends and aides of the Clintons regularly tell reporters about how close the couple, is despite operating on largely different schedules.

“I talk to him on the phone a lot,” Hillary Clinton said in May when a voter asked where her husband was.

Bill and Hillary Clinton were married in 1975 after meeting at Yale University. Their relationship has been publicly tested a number of times, including during Bill Clinton’s public impeachment trial and his affair with White House intern Monica Lewinsky.

“The most difficult decisions I have made in my life were to stay married to Bill and to run for the Senate from New York,” Clinton wrote about the Lewinsky affair in “Living History,” her first memoir.

Though the two rarely speak about their relationship, they have opened up in the past.

During Hillary Clinton’s 2008 presidential run, Bill Clinton told voters in Ames, Iowa, that early in their relationship he told Hillary Clinton to dump him so she could focus on her own political career.

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