Republicans also eliminated early in-person voting on the Sunday before Election Day, when African-Americans — 27 percent of the Democratic Party — flocked to the polls.

To get around the early voting restrictions, the Obama campaign has sought to turn the absentee-ballot period into a modified form of early voting.

As part of Obama’s Vote Now! initiative, the campaign is encouraging voters to fill out absentee ballots and, rather than stick them in the mail, head down to county election supervisors’ offices and cast them in person.

Counties typically have one or two election supervisor offices, however. Early voting precincts in area neighborhoods don’t open until Oct. 27.

Although it’s impossible to tell how a partisan voted, it’s safe to assume that the overwhelming number of Democrats who early vote are voting for the Democrat (except, perhaps, among Dixiecrat conservatives in North Florida). Republicans are going to vote for the Republican, by and large.

But what about independent and no-party-affiliation voters? They’re a mystery. And without them, a major campaign can’t win Florida. They’re a quarter of the electorate.

Right now, independents have cast about 44,000 early ballots and requested about 357,000.

If the polls are right, Romney is probably leading among independents because most of the ballots started coming in just as he whipped Obama in their first debate.

But Plouffe, the Obama advisor, suggested that polls of likely voters are missing what the Obama campaign — with its horde of more than 200,000 volunteers — is doing: Turning out new and infrequent voters.

In short, Obama’s campaign is trying to turn unlikely voters into likely voters. It’s happening with absentee votes already. Democrats are leading Republicans in absentee ballot requests among infrequent voters.

But Republicans lead Democrats when it comes to the most-reliable voters. And they’re virtually tied when it comes to new voters who requested absentee ballots.

“We think we can increase our margins in Miami-Dade,” Plouffe said. “There’s a growing Puerto Rican population in the central part of the state.”

Democrats are winning the early vote in Orange County by about 1,500 absentee votes cast — its biggest margin in any county. Of the Democratic absentee-vote total in Orange County, about 18 percent is Hispanic in a county where they comprise 24 percent of the registered Democrats. In all, more than 20,000 absentee ballots have been cast in Orange.

Republicans are handily winning the state’s most-Hispanic county, Miami-Dade, by more than 1,500 absentee ballots cast. About 78 percent of the Republican ballots here have been cast by Hispanics. They account for 72 percent of the county’s registered Republicans.

Collier County, home to financial-industry titans and conservative Midwestern snowbirds, is the Romney campaign’s stronghold. It leads Obama’s campaign by 2,300 votes in the Naples area.

Democrats are ahead in liberal Broward and Palm Beach counties. And they’re nursing the narrowest of leads in Pinellas and Hillsborough counties, which are part of the crucial I-4 corridor that’s at the geographical and ideological crossroads of the state.

Romney’s advisor, Doster, said all of the data indicates that Republicans are still more likely to vote absentee and that they’re doing a better job of casting a ballot after requesting it — a sign of positive intensity.

“We are building on a tried and true program,” Doster said. “With three weeks to go, we feel we have a strong statistical advantage.”

But the Democrats feel the same way.