Barack Obama and John Edwards joined three other Democrats in vowing to skip states that break party rules by holding early primaries, a move that leaves only a few candidates planning to compete in person in Florida and Michigan.
The decision by Obama and Edwards is a major boost to the primacy of the four early voting states - Iowa, New Hampshire, Nevada and South Carolina - and a welcome development to the Democratic National Committee, which has tried to impose discipline on a handful of unruly states determined to vote before Feb. 5.
"As I have campaigned across America over the last six months, it's become clear that Governor (Howard) Dean and the Democratic National Committee have put together a presidential nomination process that's in the best interests of our party and our nation," Obama said in a written statement.
Said Edwards, also in a statement: "Iowa, New Hampshire, Nevada, and South Carolina need to be first because in these states ideas count, not just money. This tried-and-true nominating system is the only way for voters to judge the field based on the quality of the candidate, not the depth of their war chest."
Obama and Edwards signed onto the pledge to only campaign in the early voting states a day after Chris Dodd, Bill Richardson and Joe Biden had endorsed the plan. The pledge had been circulated by Democratic leaders of the four early voting states that have party approval to hold early contests. The pledge says they won't compete in any other states that vote before Feb. 5, as Florida plans to do and Michigan is poised to do.
Their decision is a blow to Florida, which had moved its primary to Jan. 29, and Michigan, where the legislature this week voted to push its primary to Jan. 15. Michigan acted despite the DNC's threat to punish Florida by stripping it of its 210 delegates unless it comes up with another plan in the next four weeks.
The chairwoman of the Florida Democratic Party, Karen Thurman, has criticized the pledge, calling it "a pact to ignore tens of millions of diverse Americans by a selfish, four-state alliance of party insiders."
Clinton aides said Friday they were reviewing the pledge.
Clinton spokesman Mo Elleithee said the New York senator is committed to the "special role" that the four states play and that she will campaign in Iowa and New Hampshire no matter the dates of their contests.
"A number of other states are undergoing a process," Elleithee said. "And we have repeatedly said we are going to let that process play out."
The prospect of five candidates bypassing Florida and Michigan would essentially turn those contests into non-binding beauty contests, with no delegates at stake if the DNC imposed its punishment.
Party rules for this cycle had Iowa's caucuses on Jan. 14, with tests in Nevada Jan. 19, New Hampshire Jan. 22 and South Carolina Jan. 29.
New Hampshire and Iowa are considering earlier contests to maintain their influence, but the pledge does not prohibit candidates from campaigning in those states even if they go earlier than the national party allows.
Michigan Gov. Jennifer Granholm was preparing to sign legislation that would move its contest to Jan. 15, despite the threat of similar sanctions. She encouraged the candidates to ignore the pact, saying her state's manufacturing crisis and unfair trade policies were more important than the politics behind which states get to vote early.
Dodd, Richardson and Biden have the most incentive to keep the contest focused on the states approved by the DNC. They have raised less money and can't afford to organize in multiple states at the same times, especially those with expensive media markets such as Florida and Michigan where Clinton is a substantial favorite in the polls.
Financial concerns also were a factor for Edwards, who has lagged behind Clinton and Obama in fundraising. Edwards also favored caucuses in Michigan, hoping a strong labor turnout would improve his chances, but the state had been moving toward a primary.