Donald Trump and Richard Nixon have at least one thing in common: They are the two most paranoid and vindictive men ever to win the presidency. Both came to power armed with enemies lists, vowing to seek revenge against those who stood in their way. Both roamed the mansions of power late at night, raving against every perceived slight. Both were caught on tape describing the ways they enjoyed bending others to their will.

But Nixon, unlike Trump, was an introspective man. In one particularly fascinating moment of self-reflection following his resignation, he described to a former aide the habits that had enabled him to rise to the top of Washington’s greasy pole. When you’re on your way, he explained, it pays to be crazy.

“In your own mind you have nothing to lose, so you take plenty of chances,” Nixon said. “It is then you understand, for the first time, that you have the advantage—because your competitors can’t risk what they have already.” That’s an insight that Trump put to good use during the Republican primaries, when he was willing to place high-stakes bets that his more experienced rivals were unwilling or unable to match.

But then you win, and your problems begin. “It’s a piece of cake until you get to the top,” Nixon confessed. “You find you can’t stop playing the game the way you’ve always played it, because it is a part of you and you need it as much as an arm and a leg. You continue to walk on the edge of the precipice, because over the years you have become fascinated by how close to the edge you can walk without losing your balance.”

What Nixon was describing sounds like nothing so much as a seasoned heroin addict chasing the next high: It takes bigger and bigger doses to get there, until too much is not nearly enough. And a little thing like being elected the leader of the free world isn’t nearly enough to jolt a man like Nixon or Trump into rehab.