VIRGINIA BEACH, Va. _On Election Day, voter turnout will decide not only whether Barack Obama or John McCain becomes the next president, but also how much of a mandate the winner can claim.
If McCain pulls off a come-from-behind victory, polling suggests that it's likely to be a narrow one, so McCain's prospects for claiming a mandate look slim.
However, a victory for Obama, who leads in national and battleground-state polls, could break any of three ways: small, medium or large.
A narrow win could constrain Obama, though perhaps not as much as one would hinder McCain, given the Democrats' expected majorities in both chambers of Congress. A medium Obama victory could stave off the risk of Republicans contesting the election, but still might require him to move cautiously with policy initiatives.
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A landslide, on the other hand, could give Obama the leverage to push ahead with big promised changes, such as withdrawing troops from Iraq and broadly expanding Americans' health care coverage.
Were he to win states that historically have voted Republican in addition to traditional Democratic and swing states, then that, too, would strengthen his hand. So would wins spread broadly across the country rather than in concentrated pockets.
It's tempting to see these scenarios as explanations for why Obama's still raising money when he's already taken in more than $600 million, or why his campaign is calling on more than 2 million volunteers to work in the final days, and why he's returning to states such as Colorado, Pennsylvania and Iowa despite polls that show him comfortably ahead in all three.
Obama advisers insist that they're not letting themselves think past election night.
"We are solely focused on doing what we need to do to get the votes to elect Senator Obama," said national field director Jon Carson.
"Winning is the paramount thing, and the last thing I want to do is suggest in any way that we take that for granted," said Obama's top political adviser, David Axelrod, who's on the road with Obama in the final days. "We're fighting for every vote."
Axelrod acknowledged, however, that "Obviously, whenever you're in an election, the better you do, the better it is if you win, in terms of what goes on after.
"One of our goals is certainly to kind of shatter the old paradigm about red states and blue states, and you can see we're spending most of our remaining time in red states. To the extent we can shatter that paradigm in this election, I think we'll be doing a service to the country, and it will help move our politics forward in a positive direction."
Bruce Buchanan, a political scientist at the University of Texas at Austin, said that two components typically are needed for a new president to claim a mandate: a decisive win and an articulated agenda that Americans knew they were voting for.
Take Lyndon Johnson's 1964 landslide victory, when he won 61 percent of the popular vote to Barry Goldwater's 38 percent. "He ran on elements of his Great Society program, which included education and civil rights," Buchanan said. "And he was able with the victory the size he enjoyed over Barry Goldwater to lay a claim to the support of the American people for his agenda as well as just for himself."
Another mandate that presidential scholars agree on is Ronald Reagan's 10-point victory over Jimmy Carter in 1980. Reagan had promised tax cuts and increased defense spending, and he used his big margin of victory to press Congress to go along with him.
Leon Panetta, a former congressman from California who later served as White House chief of staff to President Bill Clinton, recalled: "When Reagan began to push his agenda, even though the opposing party was in charge on Capitol Hill, Reagan had this connection with the American people, somebody who clearly was enjoying very strong popularity, and that translated to a very strong force."
On the other hand, John F. Kennedy's 1960 squeaker win over Richard Nixon wasn't a mandate. Nor was Nixon's first election in 1968. Jimmy Carter's close win over Gerald Ford in 1976 was more of a post-Watergate public renunciation of Republicans than a mandate for Carter.
Even though President George H.W. Bush's 1988 victory was decisive, Buchanan said his agenda wasn't specific enough to call the election a mandate for anything.
Bill Clinton's 1992 win with 43 percent of the vote in a three-way race precluded claims of any mandate, and that may have contributed to the 1994 defeat of his big plan for universal health care.
President Bush's disputed victory in 2000 didn't give him a mandate, but the terrorist attacks on 9/11 did, and he managed to sell big tax cuts, the No Child Left Behind legislation, the Iraq war and his own re-election in 2004.
That underscores one fundamental fact about mandates, Buchanan said: "Mandates are talking points more than anything decisive."
Buchanan said it was unlikely that McCain could claim a mandate if he wins narrowly, but Obama could if he won big. "Obama's been pretty clear about middle-class tax cuts and health care, and I think he'll be able to make a plausible argument the people have endorsed these things."
If nothing else, Panetta said, "You'd have probably a much stronger honeymoon period than someone who has a narrower victory."
John Geer, a political science professor at Vanderbilt University in Nashville and the editor of The Journal of Politics, cautioned that there's a tendency for the media — and sometimes the candidates_ to exaggerate the significance of a big electoral margin.
"Usually, lopsided wins are an indication of such a statement by the public," Geer said of mandates. "But there is always uncertainty. Let's assume Obama wins by 8 points and secures over 350 Electoral College votes. Many will claim that is a mandate for his policies. But is it? Perhaps it is a statement of unhappiness with the Bush administration, and the election only means, 'Don't do what Bush did.'
"Mandates are tricky, partly because election results are not easy to read."
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