WASHINGTON — Money helped winnow the presidential field. It hasn't determined who each party's nominee will be.

Sens. Barack Obama and Hillary Rodham Clinton have proven to be mega-fundraisers, operating at near parity in their own stratosphere. Each raised $100 million last year and spent at least $80 million. On Wednesday, they each spent $1.3 million in one day for television ads in Super Tuesday states, setting the trend for the days ahead.

Whoever loses has not yet been seriously outspent.

Among Republicans, money has been less of a factor. John McCain was forced to live off the land for six months only to rise to the front of the pack. Low-budget Mike Huckabee is looking for a break, and Mitt Romney, the multimillionaire who spent $35 million of his own cash, is gasping for oxygen after two straight losses.

Rudy Giuliani, who garnered the most contributions among Republican candidates, bowed out this week after his Florida-centric strategy collapsed. And dark horse Ron Paul remains in single digits in the polls despite raising more than any of his Republican rivals in the last three months of 2007.

Money matters, but it doesn't decide.

"Raising the most amount of money by no means assures you of winning the presidential primary," said Michael Toner, a campaign finance lawyer and former chairman of the Federal Election Commission. "That said, I never knew of any candidate who didn't prefer to have more money than less."

Without substantive fundraising, Chris Dodd, Joe Biden and Bill Richardson weren't able to pitch their substantive résumés. John Edwards, however, raised about a third of what Clinton and Obama each raised and managed to stay in the hunt, jockeying for second place in Iowa before slipping away.

Early money was especially significant for Obama, who needed it to emerge as a credible alternative to Clinton. Obama has not only raised huge amounts of money, he also has created an enormous donor base. The Campaign Finance Institute, which tracks trends in political money, reported Friday that Obama raised about a third of his money in 2007 from donors who gave $200 or less. What's more, only one-third of his money came from donors who have given the legal maximum of $2,300.

Clinton raised about half of her money from "maxed out" donors and only 14 percent from donors of $200 or less. That means Obama is much better positioned to get more money from his donors than Clinton is. Obama also wowed the political establishment this week by reporting he had raised $32 million in January — a $1 million-a-day rate previously unseen in a contested primary.

"There was a wide expectation that Hillary Clinton was going to be the front-runner, and Senator Obama's fundraising success eliminated the prospect of inevitability and turned the Democratic race into a real contest," said Anthony Corrado, a campaign finance expert at Colby College in Maine.

But Clinton makes up for Obama's financial futures with name recognition, and that levels the Democratic playing field.

McCain represents the most dramatic example of the vicissitudes of money. He began 2007 with plans to be one of the party's money leaders. The campaign frittered away the money, the fundraising dried up, and McCain had to find himself anew. Comfortable in his new, lean political physique, he focused on the states that knew him best, took out life insurance to help secure a $3 million line-of-credit in late November and turned his campaign around.

Like Obama, Romney also needed to raise his profile with cash. He dipped into his personal wealth and spent even more than Obama or Clinton did in 2007. By the end of the year, his own money outpaced the money he was raising — $18 million from his own pocket to $9 million raised from October through December. But he lost in Iowa and New Hampshire, the states where he had spent most of his time and money.

"Money is still important to get you into the race," said Steve Weissman, associate director of the Campaign Finance Institute.

But Romney and Giuliani, the biggest spenders among Republicans, also proved the other side of the equation, Weissman said: "Could they get the right message out to the people?"

Romney, who made his wealth as a venture capitalist, reflected Friday on his decision to tap his wealth. He recalled that his campaign manager, Beth Myers, advised him that his rivals had spent three decades building their name recognition.

"If you're going to compete with them, you're going to have to take something of what you've built over the last 30 years and invest it in your campaign," he said she told him. "And she was right, I made that decision, and we therefore built up to a point where I'm now well recognized and I'm going to get evaluated on a, if you will, level basis with the other guys."

Campaign officials and various experts said the current state of the campaign proves that news coverage — earned media in the parlance of political professionals — can be more determinative than money.

McCain drew on his 2000 experience, revved up his Straight Talk Express bus and talked and talked to reporters as long as they were willing to stick it out. He may not have been paying for ads, but he was showing up on news shows and getting coverage. A comeback story can be irresistible.

"What's being driven home again in this campaign," Toner said, "is that earned media trumps paid media any time."