WASHINGTON (CNN) -- Democratic presidential candidate Sen. Hillary Clinton has replaced her campaign manager with a longtime adviser, Maggie Williams, the campaign announced Sunday.
The move came after Sen. Barack Obama swept three Democratic contests Saturday.
And CNN was projecting Sunday evening that Obama would win Sunday's Democratic caucuses in Maine, giving him considerable momentum heading into Tuesday's three primaries
Williams joined Clinton's campaign after her third-place showing in the Iowa caucuses January 3. At the time, Solis Doyle was urged to remain on board as campaign manager, but a senior Clinton adviser told CNN that Doyle had discussed stepping down previously. See why the shake up occurred »
"She's stepping aside," the adviser said. "She's not being blamed or nuked. She's wanted to step aside. Obviously, Maggie Williams was a transition but at the time wasn't announced."
A source close to the candidate tells CNN that Solis Doyle's job had been at risk since Clinton's poor finish in Iowa. Clinton's performance there coincided with the realization that the campaign had been running out of money -- a fact that had not been related to the New York senator until then -- but Clinton stuck with Solis Doyle out of loyalty, the source said.
Doyle has been reassigned to a senior adviser's job, the Clinton campaign announced in a memo to its staff.
Clinton's win in New Hampshire postponed the decision. But Williams began to take on many of the duties of campaign manager, and the lines of authority blurred -- senior advisers went to Williams for guidance, while the junior team was reporting to Doyle.
"There didn't need to be a dual-layer hostile environment - they just needed to sort it out," one insider told CNN. And another source added, "There was a lot of dissatisfaction with the ground operation. There was nobody in charge."
With Obama's wins Saturday in Louisiana, Nebraska, Washington and the Virgin Islands, and his projected victory in Maine, the Illinois senator took the pledged-delegate lead over Clinton -- 986-924, according to CNN calculations.
But Clinton has a 224-135 edge among superdelegates, which leaves her leading the Democratic race 1,148-1,121, according to CNN's calculations.
Tuesday, Clinton and Obama will compete for 15 pledged delegates in the District of Columbia, 70 in Maryland and 83 in Virginia.
Clinton's new campaign manager, Maggie Williams, served as her chief of staff when the New York senator was first lady.
Clinton loaned her presidential campaign $5 million in January, she said Wednesday.
"I loaned it because I believe in this campaign and I think the [Super Tuesday] results last night proved the wisdom of my investment," she said. E-mail to a friend