WASHINGTON — About six percent of US voters are still undecided in the final sprint of the White House race, boosting Republican John McCain hopes he may yet pull off a last-minute election day upset.
"Nobody knows what the margin will be like on November 4, and if it is large, the undecided will not matter," said Curtis Gans, director of the center for the study of the American electorate at American University in Washington.
"If it is narrow, it will matter."
Those indecisive Americans are being fervently wooed by both parties in the final days of a two-year White House battle.
"We can't look back and think about what might have been," Michelle Obama, wife of front-runner Barack Obama, said Saturday in the Democratic Weekly Radio Address, warning listeners not to get complacent.
"So visit your neighbors. Listen to their concerns. Tell them what's at stake. Then take them with you to vote."
Republicans too are trying to whip up the vote.
"We're working day and night to win, and in the final days of the campaign we need the resources to reach every voter through mail, calls, advertisements and personal contact," McCain's running mate, Alaska Governor Sarah Palin, said Monday.
Just who are the undecided voters?
They come from all socio-economic backgrounds, and are not easily defined, according to Gans.
"There is not only one profile of an undecided voter," Gans said.
Some have not had time to pay attention to the presidential race. Some are totally uninterested in politics, but will take the plunge and vote anyway next Tuesday.
Undecided voters are also found among those who follow politics very closely, but wait to the last minute to make up their minds.
The latest polls suggest that some undecided voters have been moving into the McCain camp as the clock ticks down.
Obama had a lead of 50.4 to 43.1 percent over McCain in RealClearPolitics' weekly average of polling data as of October 26 — with 6.5 percent still uncommitted.
But the gap had tightened to 50.3 to 44.1 percent by October 27, with undecided numbers down to 5.5 percent.
Last minute deciders can influence the outcome most of all in toss-up states, where the race is tight.
In Florida, Obama's edge over McCain is just 1.9 percent, 47.7 to 45.8 percent, according to RealClearPolitics. Whoever wins Florida reaps 27 of the 270 electoral college votes needed to win the White House.
In Indiana, with it 11 votes on the Electoral College which will ultimately pick the next president, Obama is ahead in polls by a razor thin 0.3 percent.
But unknown variables have been introduced in the electoral calculus this year, with Obama on an historic quest to become the first African American in the White House.
The stated indecision of voters could be masking ambivalence about Obama's race, according to a theory called the Bradley Effect, after an African American who lost a race for California governor in 1982 after leading in the polls.
According to the Bradley Effect, voters could tell pollsters they are undecided or even that they support Obama, so as not to appear racist, then cast a vote for the white candidate in the privacy of the voting booth.
"There are an undetermined numbers of people in America who (will) vote against Obama because of his race," Gans said. "We don't know the size of the iceberg under the surface."
But David Bositis of the Joint Center for Political and Economic Studies, a Washington think tank, discounted the theory.
"There's not some secret racist majority out there lying to pollsters," he said. At the same time, Obama will be getting "95 to 96 percent" of black votes, he said.
© 2008 Agence France Presse