Despite a continuing gray economic sky and unrest in the Mideast, the president has edged ahead of Romney in some of the most competitive states, including Iowa and Virginia, and forced Romney to redouble efforts in Florida and Ohio, without which he has little chance of becoming president.
With about six weeks left before Election Day and early voting under way in some states, Romney faces a problematic map, a ticking clock and a campaign demeanor that has failed to click with many voters.
Obama's momentum did not come overnight. It built over several weeks in which Romney hit some potholes while the president made few errors and benefited from previously unseen advantages in advertising strategy and fundraising.
Weeks of campaigning remain, and the three debates, starting Oct. 3, are the kind of events that could change the momentum again. But the race has bent toward Obama at a pivotal moment, according to public and internal campaign polls as well as interviews with leading Democratic and Republican strategists in the most closely contested states.
"Months of paid media about Romney not caring about people, being out of touch ... it came into complete focus with Romney making the case against himself," Democratic strategist Tad Devine, a top aide to past Democratic nominees Al Gore and John Kerry, said about a video that surfaced last week of Romney speaking at a private fundraiser in May.
The polls show trouble rising for Romney almost everywhere he looks. He has fallen dangerously behind in Virginia and Ohio, and his ability to close in on Obama in Iowa and Wisconsin is now in doubt.
The polls suggest that Romney must do more than inch his way up in a handful of states. He must win overwhelming shares of undecided voters, maximize the GOP's turnout, and suppress Obama's turnout where he can.
GOP officials say it's too early to count Romney out.
"Maybe he can't wait forever. But, today, a strong Romney effort offering good policy as opposed to the awful, failed policies of Obama ... will prevail," said former Mississippi Gov. Haley Barbour, a past national GOP chairman. "It's our election to win, and stakes are too high to let it get away."
Most of the polls were conducted before there was widespread publicity of the video secretly recorded in May. In it, Romney tells donors that the roughly 47 percent of Americans who do not pay income tax will support Obama and "are dependent upon government" and "believe that they are victims."
The revelation overshadowed Romney's promise to sharpen his campaign approach and offer more specific proposals to improve the economy. Democrats said the video played into their portrait of Romney as a wealthy politician out of touch with ordinary people.
Romney may not have helped himself later in the week when he released his 2011 tax return. It showed that he and his wife paid $1.94 million in federal taxes on income of $13.7 million. Their effective tax rate was 14.1 percent, lower than many families pay, because most of the couple's earnings come from investments.
Strategists in both parties have different explanations for Romney's slippage in the polls.
Some say millions of Americans started paying serious attention to the race during the two parties' conventions, when Democrats seemed to make a better impression. Former President Bill Clinton's detailed defense of Obama was especially effective, it seems.
Other campaign veterans say Romney has failed to present a cogent vision for where he wants to take the country. His message sometimes seems vague or confusing, as when he pledges to slash federal spending and then criticizes Obama for promising to squeeze $716 billion from Medicare.
Obama has his presidential powers to appeal to voters. One example was his naming of a new national monument in sharply contested Colorado.
On the foreign front, he announced new actions against Chinese export subsidies while campaigning in Ohio. That move came shortly after Romney made what was widely seen as a premature criticism of the administration in the early hours of Muslim attacks on U.S. officials and buildings in the Middle East.
Some strategists say Obama was wise to campaign aggressively during the Republican convention. He also kept his ads on the air in battleground states, while Romney went dark during the Democratic convention and stopping campaigning to prepare for the debates.
Whatever the reason for the shifts in polls, they have rocked the Romney campaign in states such as Virginia, which Romney badly needs to return to the Republican column. Until Obama's win in 2008, Virginians had not rejected a GOP presidential nominee since 1964.
A Washington Post poll of likely Virginia voters showed Obama leading by 8 percentage points, while polls by Fox News and Quinnipiac/CBS/New York Times each showed Obama with a 7 percentage point lead.
Republican campaign strategist Chris LaCivita of Virginia said the polls seem to be projecting a larger Democratic turnout than will materialize. While early voting will have begun in 30 states by the end of this week, Republicans in Virginia and other states promote their turnout machines as the keys to close states.
"Everything I see continues to show an extremely competitive race ... won or lost in the last 72 hours," LaCivita said.
But Steve Jarding, a veteran Democratic strategist in Virginia, says Romney hurt himself with talk of steep cuts in government programs, a threat to the many thousands of federal workers in the Washington suburbs. "They take pride in what they do," Jarding said.
The Romney campaign still has time, through what it calls a sophisticated system of targeting, to identify swing voters, especially after the debates. His advisers hope the three debates will let them reset the campaign after what they acknowledge has been a difficult stretch.
"Forty-some days, that's a lifetime," said Rich Beeson, Romney's political director.
Obama, Romney and groups that support them have poured millions more dollars into television advertising in Florida, Ohio and Virginia, doubling their total spending since early September to nearly $10 million last week in each of the three, according to reports of ad spending provided to The Associated Press.
Obama's spending has flattened in North Carolina, where some Democrats agree that Romney has a slight edge. Romney and Republican groups were outspending Obama there last week by $2 million to about $680,000.
Both campaigns have poured advertising money into Wisconsin in the past two weeks. Obama made his first buys there last week and has spent more than $2 million since. Romney, who had hoped to put running mate Paul Ryan's home state into play, has contributed heavily to almost $5 million in GOP spending there since early September.
An NBC poll showed Obama leading Romney by 5 percentage points in Wisconsin, and by 8 percentage points in Iowa.
"All has been slipping," said Iowa Republican Doug Gross, Romney's 2008 campaign Iowa co-chairman. "We are no exception."
In the race for the 270 electoral votes need to win, Florida (29 votes) is always the biggest up-for-grabs state, and this year it seems to hold special promise for Romney.
Unemployment there still exceeds the national average, helping his indictment of Obama's economic performance. The housing collapse has left vast numbers of homeowners in default.
Yet two polls of likely Florida voters, one by Fox News and one by NBC, showed Obama leading 49 percent to 44 percent.
The storm-delayed GOP convention in Tampa didn't rally Florida Republicans as they hoped, said Florida Democratic Party Chairman Rod Smith. Also, voters are starting to see glimmers of economic hope, he added. "I'm not saying the sun is up, but people can see that it's coming," he said.
Smith noted that Florida's new voter ID law, pushed by GOP lawmakers, may suppress the vote among some Democratic-leaning constituencies.
Palm Beach County Republican Chairman Sid Dinerstein expressed confidence. "We're very happy, very optimistic," he said.
But there is growing concern for Romney in Ohio, where no Republican has lost and been elected president, and where a Fox News poll showed Obama with a 7 percentage-point lead.
"I'd be worried if the election were held today," said Ohio Republican Chairman Rob Bennett.
(Copyright 2012 by The Associated Press. All Rights Reserved.)