New Hampshire historically has the first presidential primary, but the date will not be set until later this year, for other states are trying to push their own primaries up earlier to boost their status in choosing the parties' nominees. The New Hampshire secretary of state likely will wait until later this year to set the official date.

"It's going to be very different than any presidential election we have ever seen," Wolfson said. "This may unfold very differently than other elections."

Because there are so many candidates, the pool of key volunteers and supporters, as well as campaign donations, will be spread thinner. With only so many people and dollars to go around, experts say, campaign organizers start trying to secure these important resources well in advance of the election.

"Every election cycle it gets earlier," said Angela Ledford, an assistant professor of political science at the College of Saint Rose in Albany, N.Y. "Part of the reason they start so early is they need to raise an enormous amount of money."

Ledford said the earlier campaign season, though, runs the risk of turning voters off early.

"Voters get sick of it; there'll be absolute exhaustion way in advance," Ledford said.

Money = momentum?

But money talks. In fact, fund-raising speaks so loudly in a presidential election that just after organizing his presidential exploratory committee, Romney's supporters raised $6.5 million in a one-day fund-raising event last month. That was partly to prove there was enough support out there for him to fully get into the race, but also to show other Republicans seeking the nomination what his organization can accomplish.

Money is so important that this stage of the election is more of an "invisible primary," when dollars get counted instead of ballots and can determine who stays or goes, said David Kimball, an associate professor of political science at the University of Missouri-Saint Louis. On April 15, the Federal Election Commission requires candidates to file reports outlining all money raised for the campaign through March 31, 2007.

The FEC reports are "a big sign for momentum," Kimball said.

Like his opponents, Romney will have to raise money, but he also will use the early part of the campaign to increase his name recognition to make voters more familiar with him and enlist supporters that will attract attention, experts said.

"It is very, very, very early for voters to even be considering candidates," said Andrew Smith, associate research professor of political science at the University of New Hampshire. "They are building their organizations right now."