Examining the "demographic profile of early voters in North Carolina, Georgia and Florida, we're seeing a larger percentage of Democrats than one might expect," said George Mason University's Michael McDonald, who specializes in voter turnout. "We're seeing a larger share of African Americans than we would expect. These points taken as a whole do tell us indeed that the people who've voted so far are more likely to be Obama supporters than McCain supporters."
In New Mexico -- another state that voted for Bush in 2004 -- Democrats account for 69% of the 55,743 people who've voted early; Republicans, 31%. Those figures do not include absentee ballots, which state officials said were not available.
Nevada's two largest counties, Clark and Washoe, favor the Democrats in early voting. Nearly 172,000 people have voted, and the turnout has been 56% Democratic and 28% Republican.
In a conference call Friday, Obama campaign aides said they were encouraged.
David Plouffe, Obama's campaign manager, said: "We like what we're seeing in terms of the early vote." He added: "We might head into the election with some margin already in the bank, which is unusual for a Democrat."
Still, Republicans said they were confident. Election day turnout is how elections are decided, they said.
"We're not surprised by the strong showing by Democrats. We expected them to do well," said Brent Woodcox, spokesman for the North Carolina Republican Party.
"The Obama campaign is spending a vast amount of resources to turn out every vote they can."
The race, he added, "will be won or lost on election day, and we'll rack up a large total on Nov. 4."
Times staff writers Doug Smith in Los Angeles and David Zucchino outside Pittsboro, N.C., contributed to this report.