John Edwards said Thursday he will accept public financing for his Democratic presidential primary bid in what some saw as a concession that he cannot keep pace in money raising with his chief Democratic rivals.

"I think it's really important to take a stand," Edwards told CNN while campaigning in New Hampshire. "If you believe in public financing, you ought to be willing to take a stand for public financing."

Edwards urged Hillary Clinton, the New York senator and Democratic front-runner, to follow his lead in accepting public financing, which limits the amount of money a candidate may spend. Edwards' decision comes at a time when when he has increasingly been criticizing the influence of special-interest money in Washington politics.

The former North Carolina senator is the second major presidential candidate to say he will participate in the public financing system. The first was Republican Sen. John McCain of Arizona.

It represents a reversal for Edwards, who in February had announced that he would not participate in the public financing system. Edwards said at the time that he needed "to have the funds to be competitive."

Since then, Edwards' fundraising has been overshadowed by that of Clinton and Illinois Sen. Barack Obama. New campaign finance reports are due Sunday. As of June 30, Edwards had raised $23 million, compared with $53 million for Clinton and $58 million for Obama.

"I think that is what underdogs do when they are behind in the race for money," said Peter Francia, a political science professor at East Carolina University in Greenville. "They will call on an opponent to take public funding to equalize the playing field. Hillary Clinton and Barack Obama will be laughing at the suggestion. If it's to their advantage, Clinton and Obama will opt out of the system."

Cash now; limits later

By accepting the spending limits of the federal campaign finance system, Edwards could see a near-term infusion in public money. But his campaign would be restricted on how much he could spend.

The public financing system is paid for by $3 checkoffs on federal income tax forms. The program will match the first $250 of each individual contribution that a candidate receives during a primary.

Although the limits have not been set for the 2008 election, the Federal Election Commission has said that if the election were held this year, candidates would be limited to spending $40.1 million in the primaries.

That might not hurt Edwards, who has said his goal was to spend $40 million on the primaries.

"At one level, he could argue that it doesn't limit him in the aggregate," said David Redlawsk, a political science professor at the University of Iowa. "It simplifies raising money to hit his target because public financing would provide a big chunk. It still keeps him on target, and it fits much better with his populist campaign."

But the federal financing system also places spending restrictions on individual states such as Iowa, which Edwards has said is crucial to his presidential ambitions. The FEC said if the election were held this year, the spending limit in Iowa would be $1.5 million.

Redlawsk said it was difficult to know whether the spending limit would hamper Edwards in Iowa because he is known by virtually all the Democratic caucus members in the state and can reach the estimated 40,000 votes he needs through less expensive get-out-the vote efforts.

Edwards told CNN that he has all the money he needs to run "a serious campaign." "This is not a money calculation," Edwards said. "This is about taking a stand, a principled stand, and I believe in public financing."

Edwards plans to challenge Clinton to participate in a system of public financing, just as he has challenged her not to take contributions from federal lobbyists.

"Senator Clinton said she believes public financing is the answer to ending the influence of lobbyists and special interests in Washington," said David Bonior, Edwards' campaign manager. "If she really believes that, she should join Senator Edwards and seek public financing, or she should explain to the American people why she does not mean what she says."