Story highlights Obama holds advantage in polls in several key battleground states

Romney sees being tied with incumbent president as advantage for challenger

Romney must win all the states McCain won in 2008 and a half dozen that Obama won

GOP strategist: Romney has been resilient, must show voters he can get back on his feet

With the conventions fading into the rearview mirror and the first presidential debate fast approaching, new polls in crucial swing states suggest that GOP nominee Mitt Romney's road to the White House is becoming a more challenging ride.

Polls are a snapshot of how people feel right now. The election is still 6½ weeks away, with three presidential debates and one vice-presidential debate between now and then that have the potential to change people's minds. But the numbers in many of these new surveys seem to favor President Barack Obama over Romney.

"Throughout the spring and summer, Romney advisers would look at the mostly dead-even polls and tell me, 'I'd a lot rather be in our position than theirs,'" said CNN chief political correspondent Candy Crowley. "They don't say that now, not because it's over -- clearly whatever edge the president has can be erased. They don't say that anymore because as fall opens, advantage Obama."

Romney was asked about the new surveys in an interview Friday that will appear on CBS's "60 Minutes" on Sunday.

"Actually, we're tied in the polls. We're all within a margin of error. We bounce around week to week, day to day. There are some days we're up. There are some days we're down," Romney said. "We've got a campaign which is tied with an incumbent president of the United States."

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To win the White House, Romney needs to win all the states that Sen. John McCain carried in 2008, plus grab back about half a dozen that Obama turned from red to blue four years ago.

Romney campaigned Thursday in Florida, where two nonpartisan live operator polls conducted over the past two weeks both indicate Obama has a five-point advantage, which is within the surveys' sampling errors. Both the NBC News/Wall Street Journal/Marist and Fox News polls have the race at 49%-44%. Other, partisan surveys released since the end of the Democratic convention suggest a closer contest. Florida's 29 electoral votes are the biggest catch of the nine or so battleground states that both campaigns are heavily contesting.

In Ohio, an NBC/WSJ/Marist poll and a Fox News survey each have the president holding a seven-point lead, while an American Research Group survey shows Obama with a two-point edge, well within that poll's sampling error.

And in Virginia, a Washington Post poll indicates Obama leading by eight points, while a Fox News survey shows the president up by seven. According to a Quinnipiac University/CBS News/New York Times poll, Obama holds a four-point advantage, which is within that survey's sampling error.

President George W. Bush won all three of those states in his 2004 re-election, but Obama painted them blue four years ago.

In Wisconsin, home of Romney's running mate, Rep. Paul Ryan, a Marquette Law School poll indicates the Democratic ticket with a 14-point lead over the Republican duo. But a Quinnipiac/CBS/NYT poll indicates a smaller six-point advantage for the president, and Obama is up by five points in an NBC/WSJ/Marist poll.

In Michigan, the state where Romney was born and where his father served as a popular two-term governor in the 1960s, a CNN/ORC International poll released on Wednesday indicated Obama up by eight points. An EPIC/MRA survey released the week before suggested the president was up by 10.

Both Wisconsin and Michigan are states Democrats have long carried in presidential elections that the Romney campaign hopes to capture.

New polls in two other battleground states, Colorado and Nevada (won by Bush in 2004 but by Obama in 2008), indicate much closer contests.

"For a campaign running one to two points behind, close polls are interesting in the spring and summer. They are worrisome in the fall," said Crowley, anchor of CNN's " State of the Union ." "The good news for the Romney campaign is every and any place the president is polling below 50% -- not a comfortable position for an incumbent."

Former President Bill Clinton, who has campaigned for Obama and gave a blockbuster speech at the Democrats' convention, says the race is far from over.

"I still think you have to assume it's going to be a close race, assume it's a hard fight and then fight through it," Clinton said in an interview with Fareed Zakaria on CNN. "But I think the president has the advantage now. We did have a very good convention. He got a good boost out of it."

Romney's campaign has struggled since the conventions.

The release of secretly recorded video from a May fundraiser, in which Romney casts Obama supporters as dependent on government, dominated coverage of the race over the past week.

And the week before, there was criticism in the media and even by some Republicans of Romney's response to the attacks against U.S. embassies in Egypt and Libya.

But Republican strategist and CNN contributor Alex Castellanos says Romney has already proved this cycle that he can make a comeback.

"Despite the toughest two weeks of this campaign for Mitt Romney, these state polls tell us two things: One, this is still a jump ball; two, Obama has gotten slightly taller."

"Romney has proven resilient throughout this campaign," said Castellanos, a senior media adviser to Romney's 2008 campaign. "Now he's being tested again. He has to show voters he has presidential strength, the capacity to get back on his feet after being knocked down."

And Romney has 6½ weeks to do that.