Barack Obama defeated Hillary Rodham Clinton in Maine presidential caucuses, grabbing a majority of delegates as the state's Democrats overlooked the snowy weather and turned out in heavy numbers for municipal gatherings. Democrats in 420 Maine towns and cities were deciding Sunday how the state's 24 delegates will be allotted at the party's national convention in August. Despite the weather, turnout was "incredible," party executive director Arden Manning said. With 70 percent of the participating precincts reporting, Obama had 57 percent of the vote, while Clinton had 42 percent. The voting came a day after Obama and Clinton made personal appeals here, and after Obama picked up wins in Louisiana, Nebraska, Washington state and the US Virgin Islands. Clinton replaced her campaign manager with a longtime aide, engineering a shake-up as her presidential campaign struggles to overcome a surge in rival Obama's momentum after a sweep of weekend primary contests. The surprise announcement Sunday came hours after Obama's sweep of four contests Saturday and shortly before the Illinois senator won caucuses in Maine on Sunday. Determined to stem the tide and maintain her overall lead in the race, Clinton turned to a longtime confidante, Maggie Williams, to manage her operations. Campaign aides said departing campaign manager Patti Solis Doyle made the decision to leave on her own and was not urged to do so by the former first lady or any other senior member of the team. But it comes as Clinton struggles to catch Obama in fundraising and momentum and faces the prospect of losing every voting contest yet to come in February. Also, Clinton's campaign acknowledged Sunday that the former first lady made a private visit to North Carolina this week to seek the endorsement of former rival John Edwards, who dropped out of the race last month. Her rival Barack Obama was planning his own meeting Monday with Edwards, who confidants said was torn over which candidate to back. Solis Doyle announced the shift in Clinton's campaign management an e-mail to the staff on Sunday. "I have been proud to manage this campaign and prouder still to call Hillary my friend for more than 16 years," Solis Doyle wrote. "Maggie is a remarkable person and I am confident that she will do a fabulous job." Solis Doyle said she will serve as a senior adviser to Clinton and the campaign, and travel with Clinton from time to time. Williams, who served as Clinton's White House chief of staff, joined the campaign after the New York senator narrowly won the New Hampshire primary Jan. 8. She will begin assuming the duties of campaign manager this week. "I think this is one of the most important things I could be doing," Williams told The Associated Press.