The presidential election will be about many things. Mostly, it will be about Barack Obama.
Millions of Americans are ready for change. But many aren't comfortable with the man who's calling for it, at least not yet.
Obama's ability to reach a comfort threshold with large numbers of those voters - including those hesitant to support a black candidate - will have a huge impact on whether he defeats Republican John McCain.
Both candidates know this full well.
Speaking on the
NBC Nightly News
last week, Obama said that the Republicans want "to paint me as a very risky choice as president, partly around national security, but partly around cultural issues and, you know, he's got a funny name. And we don't know where he's coming from. . . . I think that's going to be the race they run."
McCain has raised the discomfort factor often, portraying himself as the safe pick and Obama as the risky one. "The American people didn't get to know me yesterday, as they are just getting to know Sen. Obama," McCain said last week.
On the whole, the political environment, with broad opposition to the war in Iraq and widespread concern about the economy, looks promising for the Democrats, even with the friction caused by the long fight between Obama and Sen. Hillary Rodham Clinton.
The bulk of the passion in the primaries - the high turnout and the surge in voter registration - was on their side. Overwhelming numbers of voters believe the country is on the wrong track and disapprove of the Bush administration.
Despite all those factors, McCain is running nearly even with Obama in the national horse-race polls.
Republican strategist Rich Galen, who recently worked on the presidential campaign of former Sen. Fred Thompson, said the GOP game plan would be to raise doubts about the Democrats' presumptive nominee.
"The one-sentence strategy for McCain," Galen said, "is to push this question: Who do we trust to run the world in these dangerous times?"
If swing voters are thinking in those terms come the fall, it won't be good news for the still-not-all-that-familiar, 46-year-old, first-term senator from Illinois.
Obama's goal, in turn, is to portray the 71-year-old McCain as a tired figure from the past who would deliver a third Bush term.
"Getting the country's arms around Obama involves a comparison," said Mark Alderman, a Philadelphia lawyer who is one of the candidate's leading backers. "In every way, the comparison with McCain is going to drive the situation."
Each side has to respond to the other's preferred way of framing the election.
To those who point to his lack of Washington experience, Obama will stress his judgment, energy and intellect - and hope that prolonged public exposure provides reassurance.
To those who say he's too much like Bush, McCain will talk about his reputation as a maverick and cite the occasions on which he has bucked his party, and the administration, at his own political peril.
"The Democrats want a referendum on Bush and on change," said John Brabender, a Pittsburgh-based Republican consultant who recently worked on the presidential campaign of Rudy Giuliani. "The Republicans want a campaign that takes a look under the hood of Barack Obama."
Twice in the last three decades, lesser-known candidates have managed to achieve the necessary comfort threshold, allowing them to capitalize on a public thirst for change and win the presidency.
In 1980, with the electorate eager to throw out President Jimmy Carter, Republican Ronald Reagan had to overcome doubts about whether he could be trusted with his finger on the nuclear trigger. Once he did so, he won a decisive victory.
Twelve years later, with the economy faltering and President George H.W. Bush looking out of touch, a little-known, 46-year-old Democrat named Bill Clinton had to deal with a series of issues related to this personal past. The Republicans hammered him on them.
Candidate Clinton managed to fend them off by focusing constantly on voters' economic anxieties and by behaving in a solid, reassuring way.
But the Reagan and Clinton experiences don't guarantee success for Obama.
In 1980 and 1992, the candidates who were forced to deal with comfort issues had the advantage of running against unpopular incumbents, which McCain is not. In addition, neither Reagan nor Clinton was as mold-breaking a candidate as Obama.
And in this post-9/11 world, with 150,000 American troops fighting a war in Iraq, Obama's level of foreign policy and national security experience is far more of an issue than it was for Bill Clinton in a less scary time.
"If this were 1992, Obama would be ahead by 26 points," Galen said. "This is a different era."
Debates were hugely important in both of those campaigns and figure to be so again in 2008.
"In a change election, the one-on-one meetings between the candidates take on critical importance," said David Wilhelm, who was Bill Clinton's campaign chairman 16 years ago. "Experience for its own sake isn't necessarily what people are after. They're looking for the judgment, wisdom and grace under pressure that experience is supposed to bring."
So beyond performing well at key moments, what must Obama do to make himself a more comfortable choice, assuming that America is ready to elect a black president?
One way could be to choose as his running mate a familiar and experienced Washington figure, whether it be Hillary Rodham Clinton or someone else.
In the end, though, Obama will win or lose it on his own, through how he acts and what he says.
"His message can't be so much about him and his personal story," said Paul Maslin, the pollster for Howard Dean in 2004, adding that making a better connection with blue-collar voters is the key. "It has to be about the people in this country, "about the reasons why they're desperate for change and about how he gets it."
What matters in the end is which questions - the ones about Obama or McCain - dominate over the next five months.
In politics, if you control what gets asked, you usually get the answers you want.