BOSTON — For me, the real Obama moment of this back-to-work season wasn’t the speech before Congress or Wall Street. It was in the Virginia schoolhouse when a ninth-grader asked him a question that had nothing and everything to do with his presidency: “And if you could have dinner with anyone, dead or alive, who would it be?”

The president was not about to choose Lindsay Lohan. Nor did he pick Abe Lincoln. His answer was Gandhi. Yes, that Gandhi.

“It would probably be a really small meal because he didn’t eat a lot,” he added with humor. But the icon of nonviolent leadership was his inspiration because “he ended up doing so much and changing the world just by the power of his ethics.”

As I heard this, I imagined a huge groan emanating skyward from a frustrated phalanx of his supporters. “Gandhi? Did he say Gandhi?”

These are people who spent the summer waiting for Obama’s inner fighter. The left thought he’d gotten right-wing sand kicked in his face. The media were so anxious for a battle, they got nostalgic for LBJ, urging Obama to twist arms and knock heads.

Instead they heard the man telling a polarized Congress, “I still believe we can replace acrimony with civility.” Gandhi, meet Joe Wilson.

This is the Obama story. Right from the get-go, Americans were attracted to a man who was more collaborative than combative. Hillary was the tough guy in the primaries. McCain was the warrior in the election. Obama was the Oprah candidate who believed we could talk with anyone, even our enemies.

At times, supporters urged him into trench warfare with Clinton. He didn’t and he won. At times, advisers wanted him to duke it out with McCain. He didn’t and he won.

The country liked a man who fashioned himself as a healer. And yet there has always been this underlying anxiety. Can you be a healer and a politician? If you try to mediate an ideological divide, do you just end up in the crossfire?

Michael Ignatieff, leader of the Liberal Party in Canada, recently described his transition from academic to politician this way: “It’s combat. And you have to be ready for combat, and you have to lead troops into a kind of rhetorical battle. And you’ve got to show fight. This is not a seminar.” And that’s in Canada.

Clearly, Obama knows this. But its equally clear that he wants to do this leadership thing his own way. As his would-be dinner companion would say, “Be the change you wish to see in the world.”

This is risky stuff. After all, the iconic American hero is the man who doesn’t pick a fight but is inevitably pushed into one. It’s Gary Cooper in “High Noon.”

The duality that we feel around political “combat” is not unlike the anxiety about raising boys in our culture. Parents want sons to resolve arguments without a fight, to use reason not fists. But deep in some primal place, they also believe that when push comes to shove, their boys had better be able to shove harder.

In the political playground, right and left, red and blue, have taken to their corners. Meanwhile, Obama sees himself as the principal, the grown-up. His resistance to getting riled up may come from the fear of being seen as an “angry black man.” It may also come from that old Gandhi-on-a-T-shirt wisdom that says if you get an eye for an eye, pretty soon the whole world is blind.

But those who urge Obama to adopt a new style as if it were a pair of designer jeans don’t realize just how deep this runs in his character.

“I’m skinny but I’m tough,” Obama laughingly reassured a union crowd this week. For better or worse, he is as tenacious in rejecting polarized politics as in promoting health care reform. He’s not just after a policy change but a cultural change. Indeed, he sees them as fundamentally connected.

I’m not sure he can pull it off. This is not a seminar. Joe Wilson raised hackles for disrespecting the president, but he also raised $1.5 million — for himself and his opponent. We long for and disparage a fight, we reject it and reward it.

But I am reminded of Obama’s bemused response to “60 Minutes’” Steve Kroft on the woes of being, well, nonviolent, in the polarized world, and bringing civility to politics: “It’s still a work in progress. No doubt about it.”

For the president and the rest of us.