Barack Obama realizes that many Americans don't know him well -- one reason he is running in 18 states a TV ad aimed at introducing himself.
Some who do know him from following the primary campaign may be wondering: If he becomes president, how will Obama square his call for post-partisan politics with a conventionally liberal voting record and agenda?
Democratic primary voters and denizens of the progressive blogosphere -- eagerly counting down George Bush's return to Texas -- mostly embrace a record that made Obama, according to the nonpartisan National Journal, the U.S. Senate's most liberal member in 2007.
But that might not be true for independent voters, who could determine November's outcome. They will choose between Obama's record and one that places John McCain well toward the right end of the political spectrum.
This is a genuine campaign battleground; a new USA Today/Gallup poll has 40 percent of respondents calling Obama too liberal and 40 percent terming McCain too conservative.
Which, presumably, is why Obama, in his new TV ad, speaks of his "Kansas heartland" values and specifically cites "accountability and self-reliance. Working hard without making excuses." The ad mentions, too, his work on welfare reform.
Knowing that a "most liberal" label could be toxic, Obama's camp disputes the National Journal's 2007 ratings, based on 99 votes, one-third of which Obama missed because of campaign demands. More representative, they say, is the magazine's 2005 analysis that rated him the 16th most liberal senator.
But the National Journal's assessment is not isolated. In its most recent rankings, the AFL-CIO gave Obama a 100-percent rating. Same for NARAL Pro-Choice America. By contrast, the National Taxpayers Union reports that Obama voted with its interests 5 percent of the time.
On key issues, it's hard to find an ailment for which Obama does not prescribe an expanded federal role.
Yet, he vows to bring people together on common ground. In that, he has tapped into the yearning of many Americans for diminished partisanship.
"On the level of style and demeanor and language, there's no question that the senator is trying to run a centrist-sounding campaign, and I would not underestimate the importance of style," said Pietro S. Nivola, a senior fellow in governance studies at the nonpartisan Brookings Institution in Washington, D.C.
Obama's camp notes that he, as a state senator, worked with Republicans on death penalty and ethics reform and expanding health care for children.
State Sen. Kirk Dillard, a Hinsdale Republican, is among those who lauds Obama's ability and willingness to reach across the aisle.
But Obama's Springfield record also included votes on abortion, guns and taxes that placed him squarely in company with most other Chicago Democrats.
Even Dillard, a friend and admirer of Obama, says "the fact that he works with us on selected issues doesn't mean he shares our values on core issues. He was left of even his own party on issues of crime and clearly on the far, far left on gun control."
In 2004, after a highly publicized North Shore incident, Obama voted against letting people argue self-defense if they were charged with violating local weapon bans by using a gun in their home. He cast a controversial Springfield vote against having a doctor present to provide medical care for any fetus that survived an abortion. He said the wording unconstitutionally threatened abortion rights by defining a fetus as a child. He later said he would back similar federal legislation with clarified language.
Obama's ideology mattered little in his 2004 U.S. Senate run against Alan Keyes, who anchored a spot on the far right, didn't hail from Illinois, rarely addressed state issues and ranted about gays and lesbians being "selfish hedonists."
Those who tout Obama's bipartisanship since reaching Washington often cite his work with Oklahoma Republican Don Coburn to make government operations and spending more transparent.
But detractors say he's shown little inclination to work with Republicans on Capitol Hill. They note, for instance, he did not join the Gang of 14 -- seven Republican and seven Democratic senators who in 2005 came to represent bipartisan spirit by forging a deal to discourage filibusters that could grind the judicial appointment process to a halt. Obama, his backers say, wasn't pressed to join and later praised the group's achievements.
Sarah Binder, a senior fellow at Brookings, said Obama, if elected, will try to build bridges with the GOP to ensure longer-term success for his policies and to validate his campaign rhetoric.
"Part of this rests on Republicans," Binder said, "and how willing they'll be to meet him halfway."
Noting that some issues, such as immigration and ethics, do not split sharply along party lines, Binder said success in those areas might pave the way for bipartisan efforts on more divisive matters.
Obama could appeal to centrist voters, Nivola said, by downplaying his call for raising capital gains and corporate taxes and signaling that he would name Republicans to his Cabinet.
"That would put flesh on the idea that he wants post-partisan style of structure," Nivola said.
Obama's willingness to make a more centrist pitch might not matter as much as it would have four or eight years ago. Some observers think a swinging political pendulum put in motion by dissatisfaction with Bush has the national electorate ready for the first significant liberal policy shifts since Lyndon Johnson's Great Society. In that case, a large November win could give Obama the political currency to proceed in keeping with his record so far.
"It's hard to know, frankly, what someone will be like once they're elected," Nivola said. "Franklin Roosevelt campaigned on a balanced budget; then we had the Depression, and he became a Keynesian. George Bush campaigned in 2000 as a uniter, not a divider. Then Sept. 11 came, and ever since he's sounded to a lot of people more like a divider."