Washington ? Knocked off stride by a racial uproar he helped stoke, President Barack Obama hastened Friday to tamp down the controversy. Obama, who had said Cambridge, Mass., police “acted stupidly” in arresting black scholar Henry Louis Gates Jr., declared the white arresting officer was a good man and invited him and the professor to the White House for a beer.

Obama conceded his words had been ill-chosen, but he stopped short of a public apology. He personally telephoned both Gates and Sgt. James Crowley, hoping to end the rancorous back-and-forth over what had transpired and what Obama had said about it. Trying to lighten the situation, he even commiserated with Crowley about reporters on his lawn.

Hours earlier, a multiracial group of police officers had stood with Crowley in Massachusetts and said the president should apologize.

It was a measure of the nation’s keen sensitivities on matters of race that the fallout from a disorderly conduct charge in Massachusetts — and the remarks of America’s first black president about it — had mushroomed to such an extent that he felt compelled to make a surprise appearance in the White House briefing room to try to put the matter to rest. The blowup had dominated national attention just as Obama was trying to marshal public pressure to get Congress to push through health care overhaul legislation — and as polls showed growing doubts about his performance.

“This has been ratcheting up, and I obviously helped to contribute ratcheting it up,” Obama said of the racial controversy. “I want to make clear that in my choice of words, I think I unfortunately gave an impression that I was maligning the Cambridge Police Department and Sgt. Crowley specifically. And I could’ve calibrated those words differently.”

The president did not back down from his contention that police had overreacted by arresting the Harvard professor for disorderly conduct after coming to his home to investigate a possible break-in. He added, though, that he thought Gates, too, had overreacted to the police who questioned him. The charge has been dropped.

Obama stirred up a hornet’s nest when he said at a prime-time news conference this week that Cambridge police had “acted stupidly” by arresting Gates, a friend of the president’s. Still, Obama said Friday he didn’t regret stepping into the controversy and hoped the matter would end up being a “teachable moment” for the nation.

“The fact that this has garnered so much attention, I think, is testimony to the fact that these are issues that are still very sensitive here in America,” Obama said.

Obama wryly took note of the distraction from his legislative efforts.

“I don’t know if you’ve noticed, but nobody’s been paying much attention to health care,” the president said.