If you believe the polls, it would appear there is one big factor standing in the way of Mitt Romney being elected president: Americans don’t like him as well as they do President Barack Obama.

That was confirmed again in a new USA Today-Gallup survey, where respondents gave Romney higher marks on every issue that voters say they care most about this year — the economy, jobs, taxes, the deficit. But Obama crushed Romney — 60 percent to 30 percent — on the question of which of the two was more likable.

The presidential race throttles into its last 100 days as an enormous clash over economic vision, with the outcome likely to come down to fall debates, final unemployment numbers and fierce efforts to mobilize voters.

It may seem like an election for the whole nation, but only about eight states will decide who wins the White House.

In April, a Washington Post-ABC News poll found an even larger likability gap, with 64 percent of those surveyed describing Obama as the friendlier, more likable candidate, and only 26 percent saying that about Romney.

“We’re not going to win a personality contest. It’s not an election for class president. It’s who can best solve the problems of the country,” said Romney’s own pollster, Neil Newhouse. “Likability isn’t fixing the economy or helping the middle class make ends meet.”

In part, the disparity reflects a natural reserve, even awkwardness on Romney’s part. It also reveals a sensitivity to the fact that there are upsides and downsides politically to defining himself through his biography — his Mormon faith, his spectacularly successful business career, his wealth and his stint as the governor of a liberal state.

Asked last week by NBC News’ Brian Williams whether he is “unknowable to us,” Romney said he is trying, and still has opportunities to introduce himself.

“You know, I’ve been on ‘The Tonight Show’ and Letterman and ‘The View,’ and I do some of those things to get better-known,” he said in the interview. “But at the same time, most folks won’t really get to see me until the debates and will get a better sense of the character that I have.”

Romney also seemed to acknowledge that he is not exactly a natural when it comes to selling the inner Mitt. “My wife and my sons and daughters-in-law, they’re doing the best job they can to get the real story about who I am in public view,” he said.

In every election for the past two decades, the candidate viewed as more likable was also the one who won.

Voters look at the ballot with the expectation that they are going to have “a pretty intimate relationship with the president,” said Obama’s chief political strategist David Axelrod. “In addition to everything else, they know they are going to see a lot of him.”

Axelrod added, “Likability is a hard thing to measure.” The two candidates will intensify their time before voters in the weeks ahead, knowing much of the public will not truly start paying attention until after Labor Day.

What voters probably will see will look a lot like what’s played out so far — a bitter, bruising, personal contest over who can be trusted to fix the economy. Obama himself is no one’s idea of a glad-hander.

What makes people warm up to a candidate, Axelrod said, is a sense that he is “someone who is accessible to me, someone who understands me, someone I can relate to.”

Those perceived qualities about the president, strategists on both sides say, have helped keep the race a close one, despite Americans’ disappointment with how the economy has performed under Obama.

“Likability is keeping Obama in the game at this point,” said Mark McKinnon, a top strategist for president George W. Bush, who in his 2004 re-election bid was famously deemed in one poll to be the candidate with whom undecided voters would rather have a beer.

“But Romney has a lot of potential to improve his likability numbers, particularly during the convention,” McKinnon added. “Romney hasn’t really revealed much of his personal story or his personality, so he’s got a lot more potential to grow.”

The upcoming stretch is loaded with opportunities for the candidates to capture the public’s imagination, land a big blow or flub a chance. Romney is closing in on his vice presidential nominee, he and Obama will give highly scrutinized convention speeches, and the two will face off three times in October debates.

Then there are the surprises — be they national events or scares from abroad — that can jolt the campaigns and test the candidates.

“We’re all looking for that moment,” said David Gergen, a political analyst who has advised Republican and Democratic presidents. He predicted it could come in the first debate, in Denver on Oct. 3, when Obama and Romney finally stand on a stage together and go at it over economic policy.

GOP strategists within and outside of the Romney campaign insist that he still has plenty of time to acquaint the American people with his softer side, and that, given all the problems the country faces, personality will not be the deciding factor this election year.

Sounding a bit like a sympathetic psychotherapist, a recent Republican National Committee ad acknowledged Americans’ affection for Obama and offered them permission to move on.

“He tried. You tried,” the announcer said. “It’s OK to make a change.”

The Associated Press contributed to this report.