Common wisdom is usually an oxymoron: if it’s common, it’s usually scratch-’n-dent wisdom, at the best. And no wisdom is more common, and less wise, than the idea that Barack Obama would do himself a world of good if he would only dial up the aggression. In short: no, he wouldn’t, and pundits who continue to harp on this idea only reveal their own mainstream cultural insularity. And lack of imagination.

Let’s begin at the end. Obama faced off against John McCain on Friday night, the culmination of a long week of erratic mood swings by the Arizona Senator. The upshot of that head-to-head meeting was crystal clear, far clearer than these post mortems usually manage: every poll taken showed that Obama had helped himself significantly, with nearly every demographic.

Obama’s tracking numbers doubled. Prominent Conservatives, folks like George Will and Dick Morris and Charles Krauthammer, grudgingly gave the win to Obama.

Now, it may seem like pointing out the obvious, but in order to put the Obama-lacks-punch meme to rest, it’s unfortunately necessary: when you debate, or campaign, you want your numbers to go up, not down.

Just so we’re clear on that. Obama did what one wants a candidate to do Friday night. He made himself the preferable choice.

So anyone who says that Obama could have “closed the deal” or “knocked McCain out” by upping his level of aggression is mad. And not just mad, but blind to the history of this campaign: at every single stage of the long, two-year game, Obama has been criticized for lacking aggression.

And yet he has advanced at each stage, made voters like him, settled any lingering uneasiness, moved forward smoothly and without great fanfare.

When he was part of a three-candidate field, and neck and neck with Edwards behind Hillary, the conventional wisdom was that he needed to punch his way clear of them.

Maureen Dowd captured this meme in her mocking nickname, “Obambi.”

And that image has delighted Conservatives, for whom it extends to a general critique of supposed Democratic softness on security issues.

Then it was Obama versus Hillary, and everyone exhorted Obama to hit harder, to pound her into withdrawing from the race.

Then, after he’d secured the Democratic nomination, Obama faced attacks from John McCain on his so-called celebrity status, and ads that linked Obama with Paris Hilton and Britney Spears.

Get mad, James Carville said. Use the meat-cleaver that Bill Clinton liked to talk about back in the day.

And here we are in October. Obama is up by 6-9 points in the daily tracking polls; he’s breaking open the electoral map.

Can someone, somewhere, some time or other, please consider the possibility that an African American man growing up in America might have some small idea about how hard he can hit without actually hurting himself?

Take a look at the photo at the top of this post again. Barack Obama has spent his life negotiating not just predominantly White American culture, but predominantly Asian cultures, and predominantly Black American cultures.

His success and his identity are inseparable from his ability to guage how hard he can push, without provoking backlash, without accentuating his own difference, without bringing out the worst in those around him.

He has not succeeded brilliantly thus far in spite of his “Think Thrice Before Striking” attitude, but because of it. Anyone who thinks it an accident that Obama has gone where no other African American man has gone before simply isn’t thinking.

It’s not that Obama has adopted passivity as a political or social stance. Far from it. His campaign has counter-attacked, and their attacks have had real bite. But when Obama does hit back, it is almost always after a consensus has developed that he’s justified in doing so. Hillary’s campaign came off looking mean and occasionally thuggish as a result; McCain’s campaign has gone even further down the same road.

Obama has developed an almost preternaturally accurate sense of how to avoid the stereotypes that continue to dog African American men in the twenty-first century, and it is typified in his strategy.

So again, if anyone in America is qualified to say precisely how hard Barack Obama can hit without hurting himself, that man is Barack Obama.

When his numbers slide dramatically, and his prospects for the White House go dim, then we’ll be willing to listen to armchair quarterbacking from white suburban pundits and politicians, those who’d like to see a little more blood sport and who can’t be troubled to do their homework.

Until then, not so much.