With Senator Clinton racking up a string of recent defeats in the Democratic presidential contest, her campaign manager is departing and being replaced by an aide who served as Mrs. Clinton's chief of staff during her years as first lady in the White House.

The installation of the campaign's new chief, Margaret Williams, and the departure of the former head, Patti Solis Doyle, came as Mrs. Clinton's rival for the nomination, Senator Obama of Illinois, yesterday swept caucuses in the state of Maine. Mr. Obama won 59% of the delegates to the state convention that will select national delegates, while Mrs. Clinton had 41%, with 91% of the precincts reporting. On Saturday, Mr. Obama also prevailed by healthy margins at caucuses in Nebraska, Louisiana, Washington, and the Virgin Islands.

Hours after the switch was announced, Clinton lost the Maine Democratic caucus to Obama in another staggering defeat. Television networks and the Associated Press declared Obama the winner by a significant margin with 70 per cent of the vote counted.

Clinton campaign officials didn't say whether Sunday's shift was connected to Clinton's resounding double-digit defeats to Obama in Saturday's Louisiana primary and Nebraska and Washington caucuses.

Saturday and Sunday's losses came after a week in which Clinton acknowledged that she quietly loaned her campaign - which had raised more than $100 million in 2007 - $5 million last month in order to keep pace with Obama's aggressive television advertising blitz in key states.

While some aides described the loan as a solution to a temporary cash flow problem, some Clinton supporters saw it as a sign of a campaign in distress. Obama's campaign raised $32 million in January while Clinton's raised $13 million. Clinton officials say they've raised another $10 million from 100,000 donors since the Feb. 6 Super Tuesday contests.