It would be hard to imagine a greater gift than the sound bite that Barack Obama handed to Republicans on Friday: “The private sector is doing fine.”

At a moment when the president is struggling to connect with the economic anxieties of the American public, that statement is likely to show up again and again in attack ads, conservative commentary and Republican stump speeches between now and November.

Those six words now stand as Exhibit A in the GOP’s case that, as Obama’s opponent Mitt Romney put it minutes later, the president is “detached and out of touch” on the issue that ranks at the top of voter concerns.

Republicans know well how toxic and corrosive one such remark can be. In 2008, their own nominee, John McCain, never recovered from his declaration that “the fundamentals of our economy are strong,” even as the financial system was melting down that September. And it was then-candidate Obama who had mocked him: “Senator, what economy are you talking about?”

As the Republicans rushed to make the same point about Obama — in public statements by their leaders, a Web video and a Twitter chorus with the hashtag #doingfine — the president sought to clarify his comment during an Oval Office appearance with Philippine President Benigno S. Aquino III.

“The economy is not doing fine,” Obama said. “There are too many people out of work. The housing market is still weak, too many homes underwater, and that’s precisely why I asked Congress to start taking some steps that can make a difference.”

Indeed, that argument — that Republicans should quit blocking his initiatives aimed at giving local and state governments funding to retain teachers, firefighters and police officers, as well as for new infrastructure projects that would help revive the construction industry — had been the White House’s chief goal in scheduling the impromptu news conference in the media briefing room. But it was all but lost in the furor that followed Obama’s sanguine comments about the state of the private sector.

In part, the whole episode underscored the degree to which the president is struggling to find his footing in his reelection campaign, which is a far different challenge from the one he faced when the first-term Illinois senator made his long-shot bid for the presidency four years ago.

Unlike in 2008, when Obama could position himself as a fresh face and an agent of change, he now must defend his record while also making the case that things will get better if voters rehire him for another four years. There’s still another imperative: to show that his policies are superior to those of his opponent, and that his priorities are closer to those of most Americans.

While this is a challenge that every president faces in a reelection bid, the degree of difficulty is greater when times are hard and the mood of the electorate is sour. As formidable an advantage as the power and trappings of the presidency are, they can also be an enormous weight.

And Obama’s style tends more toward the professorial rather than making a gut connection, which is one reason he got himself into trouble Friday at his news conference.

The president’s point, which he made several times, was that businesses are expanding, however modestly, while state and local governments are laying off workers.

But that did not speak to the anxiety that Americans are feeling about their own employment prospects, nor to the anger that is building over the fact that corporations are sitting on record amounts of cash rather than using it to hire.

“To say, as a general statement, that the private sector is doing fine conveys a sense of satisfaction with the overall economy that I know he doesn’t feel, and that the voters don’t feel, and that the Republicans are going to jump on,” said economist Robert J. Shapiro, who was a top policy adviser to President Bill Clinton.

Obama himself expressed frustration that “instead of actually talking about what would help, we get wrapped up in these political games. That’s what we need to put an end to.”

An American president is uniquely positioned to get that conversation going. In the bully pulpit, Obama has the closest thing to a guarantee that when he speaks, every word will matter.

That, as he discovered Friday, has both its benefits and its perils.