It's a voluntary army vs. a professional force. Button-down Republicans vs. street-wise Democrats. It's the ground war of American politics, with allies of President Bush and Sen. John Kerry (search) spending fortunes to find their supporters and — here's the hard, final part — get them to vote.

Until then, nobody will know whose battle plan is the smartest.

"I wish I did," said Bush campaign manager Ken Mehlman (search). "There's no doubt in my mind that we're going to win the turnout battle, but until after Election Day it's always hard to separate increased turnout due to momentum of the candidate vs. increased turnout as a result of the organization."

"One thing's for sure," he said, "neither side is giving an inch."

Not with this much at stake.

Four years ago, Bush went into Election Day leading in most opinion polls and ended up losing the popular vote, a development Democrats attributed to their get-out-the-vote campaign. In 2002, Republicans credited their unusually strong ground campaign for gains in Congress.

Now, Bush and Kerry are locked in a close race — both counting on their voter-contact operations to carry the day.

With multimillion-dollar investments in state-of-the art technology, both campaigns use Census and other data to track voters down to the household level in dozens of ways — from their voting habits to their magazine subscriptions, their church affiliations, race, age, marital status, number of children, hobbies and political issues of interest.

More than 105 million people voted in 2000, about half of those eligible, when Bush defeated Al Gore in one of the closest elections in the nation's history.

Democratic voters "saw in 2000 how every vote did count," said Michael Whouley (search), Kerry's chief strategist at the Democratic National Committee (search). Whouley was a top adviser to Gore during the challenge of Florida's election in 2000, which ended with a 537-vote victory — and the presidency — for Bush.

That margin is a powerful motivator.

Long before knowing who would be the Democratic nominee, party powerbrokers and special interests formed a rare alliance to raise and spend money against Bush. Much of it paid for television commercials while Kerry found his footing after the Democratic primaries, but tens of millions also have gone into the ground war.

The biggest organizer, America Coming Together (search), has a budget of $125 million — at least four times what the Democratic Party spent getting out the vote in 2000.

Kerry's own operation is dwarfed by ACT, which has more than 4,000 paid staff in 13 states making 12 million telephone calls and delivering 11 million fliers to doors in the last three weeks of the campaign.

On Election Day, ACT promises to have 45,000 people — earning $75 a day — rounding up votes in Ohio, Florida and Pennsylvania.

America Votes Partners, a coalition of 33 interest groups such as the AFL-CIO and Planned Parenthood, will mobilize thousands more workers. The group's president, Cecile Richardson, sniffs at the mostly volunteer GOP effort.

"It's one thing to talk a good game," she said, "it's another to have people on the streets."

Republicans say they'll have plenty of people pounding pavement, starting with tens of thousands of paid workers on Election Day. But they say the beauty of their operation is its reliance on highly motivated volunteers who are closely monitored by Bush's headquarters in Arlington, Va.

The campaign's Amway-like business model sets goals for each volunteer and tracks their progress. It's an intensely personal approach that people like Laura Hemler believe is the future of American politics.

The 36-year-old mother of three from suburban Minneapolis has been in politics just two years, but she co-chairs Bush's campaign in Minnesota's most populous county, Hennepin.

"I've seen the Democratic groups standing on corners signing people up. That doesn't impress me to have hired guns in here," she said. "They don't have any skin in the game. You have to know people to persuade them."

Hemler had just gotten home from a neighbor's house, where she had coffee with 40 other suburban women. "You're most effective when you work one-on-one."

Both parties claim success in the first stage of the ground game — registering voters and getting them to vote early.

In the past four years, more Democrats than Republican have registered in Iowa, Arizona, Nevada, New Mexico, New Hampshire and Maine. Republicans made gains in Florida, Colorado, Oregon and West Virginia.

But new independent voters outnumber newly registered Democrats and Republicans in most of those states. Who will they vote for?

"We don't know," Mehlman said. "Wish we did."

There is nothing certain about turnout, even to a hard-nosed strategist like Whouley. Democrats are highly motivated, he said, but "we have to turn that enthusiasm into hard votes."