Obama mastered his demons. Trump nurtures his.

US President Barack Obama speaks while meeting with President-elect Donald Trump (L) following a meeting in the Oval Office. Photo / Getty

Politicians are desperate people. That was the premise of a question David Axelrod posed to President Barack Obama in a podcast earlier this week. Their exchange on the topic will become especially poignant on January 20, when the erstwhile non-politician Donald Trump is sworn in as Obama's successor.

"Most politicians have some sort of wound," said Axelrod, who has worked with dozens of candidates for House, Senate and statewide offices as a Democratic media consultant. "I find, especially at a higher level, that something happened in their childhood, and they really need the approbation of the crowds and the affirmation that comes with being elected."

What Axelrod was asking the president was the big question I've always harbored about Obama: Where's the hole? Where in Obama is the insatiable hunger, the vast, unfillable void that drives someone to the daily madness of running for the American presidency?

Has Obama truly defied what even his close friend and adviser understands is a dominant rule of political character - one that's evident not only in extremes such as Richard Nixon and Anthony Weiner, but in George W. Bush and Bill Clinton? Or is Obama just especially ingenious at camouflaging his need? Even that would require a level of self-awareness, and self-correction, that few national politicians can muster.

As it happened, the "news" from the Axelrod podcast was something different, yet intimately related to the question of the hole. Obama claimed in the interview that he could have won a third term, though he didn't use those exact words. The president's statement was more nuanced than a plain boast, and rendered in service of a larger point: that the "Obama coalition," an electoral majority that twice had carried him to victory, was only sleeping, not dead.

"You know, I am confident in this vision because I'm confident that if I - if I had run again and articulated it," Obama said, "I think I could've mobilized a majority of the American people to rally behind it."

Obama could have made the point without reference to himself. Surely he knew, even as the words departed his mouth, that Trump would find the claim an intolerable taunt.

After two historic victories, and on the verge of leaving office with broad public approval, perhaps Obama was showing just a little bit of the wound that Axelrod described.

Here is Axelrod reminiscing in the podcast exchange about Obama telling him that he wanted to run for president:

"I don't know if you remember this conversation I had with you when you were - when you came to my office, right? You got back from Hawaii, you're about to make the decision to run, you come in unannounced and we talked for a long time. And I told you, I'm not sure you're pathological enough to run for president.

"(LAUGHTER)

"And what I meant by that was I didn't think you had that sort of pathological need that so many people who run for president do. And I don't know why that is because your dad abandoned you basically when you were two years old. And your mom - I know she was very loving, but you were separated from her for long periods of time. And if you were just looking at those facts, you'd say yeah, this guy's gonna be a real needy person."

Obama responded with a few points: first, his character had time to develop because he achieved success relatively late in life; second, he felt unconditionally loved by his mother, despite her long absences; third, his marriage to Michelle had grounded him.

To people who have witnessed the hole in countless other politicians, it's not a completely convincing answer. Yet even on occasions when Obama appears overly competitive or arrogant, it generally comes off as an arrogance anchored by authentic cockiness, not raging insecurity. "No Drama" Obama has let countless slights, many of them racist and despicable, evaporate.

For Trump, however, every day is anchors away. His hole is larger and more conspicuous than any we have seen in a president. Nixon covered his rage and pain with expertise, ingenuity and hard work. Clinton, likewise, erected a scaffolding of policy diligence and political brilliance across the chasm.

Trump's incessant neediness is perhaps the only governing principle of his chaotic personality. But it's too vast and flamboyant to be camouflaged. His inability to sustain a slight, and his toddler's mad ferocity in retaliation, expose him time and again.

He has tried to fill his hole not with knowledge or expertise, which can buttress a shaky politician in a weak moment, but with fame and money and a blunt drive to dominate others. Only the last offers a tactical advantage as president, although at the risk of inspiring lasting resentments and alienation. Fame and money will be useless after Jan. 20. In the White House, all is magnified and enlarged. Trump's hole will be, too. It will either consume him, or it will consume us.

- Wilkinson writes editorials on politics and U.S. domestic policy for Bloomberg View.