By RODNEY HO/ rho@ajc.com, originally filed Wednesday, September 23, 2015

In a pre-taped interview before he announced his stage 4 melanoma last month, President Jimmy Carter spoke with Oprah Winfrey for her show "SuperSoul Sunday," which airs on the OWN network this Sunday at 7 p.m.

He discusses his faith as the first evangelical Christian elected president and how that guided his decisions. He talks about the secret behind his nearly 70-year marriage to Rosalynn. He also says he could not possibly be president today in the current political environment.

"Absolutely not. There's no way now for you to get the Democratic or Republican nomination without being able to raise two or three hundred million dollars, or more, and I would not be inclined to do that. And I would not be capable of doing it. We've become now an oligarchy instead of a democracy. And I think that's been the worst damage to the basic moral and ethical standards of the American political system that I've ever seen in my life."

This is Carter talking about his marriage:

"She was the right person. That's the first thing," President Carter tells Oprah. "And then, we decided fairly early in our life to give each other plenty of space. Rosalynn has her own ideas, her own ambitions, her own goals in life, which, in some ways, are different from mine. I let her do her thing; she lets me do my thing. And we try to resolve our inevitable and fairly frequent differences before we go to bed at night."

Here's a clip of him discussing how he would rate his presidency 35 years later: