This year's presidential candidates are running neck and neck for the White House and with high voter turnout expected, this year's elections could be made or broken by how well each party gets its supporters out to the polls.

"It's going to be a turnout election," said John Kasich (search), a former U.S. representative from Ohio and host of FOX News' "Heartland."

Democrats and Republicans have been sparring over who has a better game on the ground to register voters and encourage them to go to the polls. Kasich said he thinks the Democrats have been more effective in registering new voters. He estimates a 60 percent to 40 percent advantage over the Republicans. But the question is: Will the people they have registered show up at the polls?

For example, in a prime battleground state like Ohio, which has 20 electoral votes, analysts say 800,000 new voters have registered. If a larger number of Democrats than normal show up at the polls, Democratic challenger John Kerry (search) could feasibly win the state, Kasich said. But if turnout remains at normal levels, President Bush (search) will win the state like he did in 2000.

Presidential adviser David Gergen (search) said Bush has some work to do convincing new and swing voters that he's the best man for the job.

"I think the Republicans have the best ground operation they've ever had in their history … what they have to worry about is the Democrats [also kicking up their game],” Gergen said. "In those final 72 hours or so, people are going to break one way or the other — conventional wisdom is they break against the incumbent."

"[Bush has got to] defy history here and have the late-breaking voters come his way," Gergen said.

GOP strategist Bill Simon said he believes that will be the case.

"I think the undecideds will break in favor of the incumbent," he said.

Voter registration is up in many key states. Iowa has registered 80,000 new voters for this election. One million voters have been registered in Florida since Feb. 1, bringing the Sunshine State 1.5 million more voters this year than in 2000.

In the battleground state of Pennsylvania, the Democratic Party has registered 108,000 more new voters than the GOP since the April primary. Democrats now have nearly 4 million people on the voting rolls there — a 7 percent increase — while GOP ranks increased by 4 percent to nearly 3.4 million.

The number of registered voters in Pennsylvania stands at a record 8.2 million, a 6 percent increase since April. Of 437,896 new registrants, 247,207 are Democrats and 138,864 are Republicans, according to unofficial totals from all 67 counties.

FOX News political analyst Eleanor Clift noted that in the 2000 election, 105 million to106 million people voted. But this year, an estimated 110 million to 115 million are expected to go to the polls.

"I think there still could be a decisive victory [for one candidate or the other],” Clift said.

Democratic National Committee Chairman Terry McAuliffe said his party is raising more and spending more money than the Republican National Committee two to one in terms of funds for ground efforts.

"That's never happened before. Everything's going our way right now," McAuliffe said.

Republican strategist Frank Donatelli said both candidates are running a strong ground game.

"Our game is much more centralized — Democrats outsource them to 527s," he said.

So-called 527 groups — named for their IRS designation — operate independently of candidates, but fund attack ads on a candidates' behalf. They have become a powerful political force with little accountability. Many such groups, like the MoveOn.org, Swift Boat Veterans for Truth, Association of Community Organizations for Reform Now, America Coming Together and the Progress for America Fund, have been out in full force this campaign season, registering new voters left and right in an effort to drive people to the polls.

But questions are surfacing about the activities of some of these groups. For example, ACORN's voter registration efforts in Florida are under investigation there. ACORN is also under scrutiny in the battleground states of Ohio, Missouri, Michigan, New Mexico, Colorado, Wisconsin, Minnesota and Pennsylvania.

"We have a situation where Senator Kerry's campaign, both in its advertising and its registration efforts, are relying upon these shadowy 527 groups," Bush-Cheney campaign spokesman Dan Bartlett told FOX News. "And in Defiance, Ohio, for example, it was learned that one of the people who was registering people to vote was being paid with crack cocaine. I mean, this is the type of environment we are working in now, in which we're seeing fraudulent efforts to try to rig this election. And that's not what we need."

ACT has 86 offices open daily with a staff of 4,000, an additional 45,000 paid canvassers and 25,000 volunteers in various states on the ground. On Election Day, this group will have spent over $10 million on its efforts.

America Votes’ 33 coalition partners, mainly Kerry supporters — including the AFL-CIO, NARAL, Young Voter Alliance and the League of Conservation Voters — are launching a huge get-out-the-vote effort and have invested more than $400 million to mobilize voters. The group will mobilize 30,000 volunteers and hundreds of thousands of voters in targeted precincts on Election Day. Half will be recruited from "non-battleground" states including Texas, California, New York, Illinois, Maryland and New Jersey.

Both Bush and Kerry are hoping that by bringing big stars like former President Bill Clinton and former New York City Mayor Rudy Giuliani will also help push voters to cast their ballots.

And on college campuses, GOP and Democratic student groups are also trying to encourage young voters to go to the polls.

Michael Davidson, chairman of the California College Republicans, said that his state organization had under 1,000 members two years ago. Now, they have 10,000. The group goes door-to-door on college campuses in a big push to get students to request absentee ballots so they can vote since many don't live in the area where they go to school.

"There's certainly something in the air that's getting young people involved [this year]," Davidson said

Davidson said that events like the 2000 election debacle and the Sept. 11, 2001, terror attacks brought out a lot of enthusiasm for young voters to get involved in the process.

Alex de Ocamp of the California Young Democrats said young Americans are more worried about issues such as war, education and jobs, than they ever have before.

"We're definitely seeing many young people mobilizing as we near Nov. 2," Ocamp said.