(CNN) It's going to be the political question of this era: Is President Donald Trump crazy like a fox? Or is it something else?

There's no precedent for the mercurial Trump, but there is what Richard Nixon called the "madman theory," according to his chief of staff, H.R. Haldeman, and it's pretty simple: Nixon consciously tried to portray himself as unstable to give himself a hand-up over US adversaries in the Cold War.

Nixon's aides, including Haldeman and national security adviser Henry Kissinger were complicit in the gamesmanship, according to Haldeman's writings and recordings of Nixon and Kissinger . They knew he wasn't rushing to set off a nuclear weapon. But the Russians, as the theory goes, couldn't be so sure. After all, Nixon was a "madman."

Or was he?

Presidential historian Tim Naftali, a CNN contributor and the former head of the Richard Nixon Presidential Library and Museum, said the madman theory has grown in time into a bigger deal than it actually was.

"Nixon's theory has been hyped into some kind of formal strategy," he said in an email. "It may have been tested once, then was dropped."

Trump's lack of predictability extends further than any notable predecessor, and there is no clear rhyme and reason to his behavior -- much less a coherent strategy. There's little evidence to suggest he's doing more than taking issues as they come each day, hopping from lily pad to lily pad and doing his best to make it look like he plotted his jumps. Unconstrained by any obvious political ideology, he is free in a way to go about trying to build a wall and make better deals for the US by any means he chooses, in any given moment.

Naftali differentiated between the madman theory and pragmatism, suggesting the latter was a part of Trump's behavior and pointing out that he ran as a dealmaker.

Nixon, by the way, worked with Democrats on social welfare and environmental legislation. He had to: They controlled the House and Senate.

Republicans run everything in Washington today, but they now know that if they don't get things done for Trump, he'll work with Democratic leaders Chuck Schumer and Nancy Pelosi -- like on the debt or the Deferred Action for Childhood Arrivals (DACA) program. It wasn't a decision he wrestled with, but it appeared to come to on a whim, in the middle of a meeting on funding the government, hurricane relief and raising the debt ceiling. He just sided with Democrats. Just like that.

He liked the results so much he worked with Democrats again -- or started to -- on DACA and border security. (That effort is still a work in progress, ahem.) In a Washington, DC, paralyzed by politicians in their foxholes, that's basically the nuclear option.

Trump, in the way Nixon wanted the Russians to think he might hit the button first, wants people to think he'll insist on building a wall and maybe even shut down the government, even though it's unclear he wants to or will be able to do either. And if you doubt this, see the transcript of his call with the Mexican president from earlier this year, published by The Washington Post

JUST WATCHED Trump 'fairly close' to a DACA deal with Dems Replay More Videos ... MUST WATCH Trump 'fairly close' to a DACA deal with Dems 01:00

But credibility still matters.

The potency of his unpredictability will be lost if people stop believing him entirely. He promised "fire and fury" if North Korea carried on with missile tests. Those comments frightened a lot of people. But they didn't stop North Korea from carrying on. Trump has unleashed some fury, but no fire in the aftermath. He hatched the beginnings of the DACA deal with Pelosi and Schumer, but the ensuing outrage among conservatives had him on the back foot almost immediately.

Still, it's hard to recall former President Barack Obama doing anything terribly shocking. "No drama" was his organizing principle and you could pretty much guess what he'd do on any given thing. (One exception... the time he surprised the heck out of this writer was when he sang " Amazing Grace " at a service honoring Charleston shooting victims.)

Trump thrives on surprise. Nobody -- not even the President -- seems to know what he's going to do or tweet about next, which is part of the reason he's made politics such an incredible, shocking jarring thing to watch for the past two years -- like it or not.

Regardless, it's going to be a show. One with a swerving plot line, wild narrative digressions and an unpredictable lead, center stage at 1600 Pennsylvania Avenue.