Democrat Hillary Clinton has replaced her campaign manager Patti Solis Doyle.
Ms Solis Doyle announced the shift in an e-mail to the staff today, with Mrs Clinton’s aide Maggie Williams taking over.
“I have been proud to manage this campaign and prouder still to call Hillary my friend for more than 16 years,” Ms Solis Doyle wrote. “Maggie is a remarkable person and I am confident that she will do a fabulous job.”
The move comes a day after rival Barack Obama swept to victory in contests in Washington state, Nebraska, Louisiana and the US Virgin Islands.
Ms Solis Doyle said she will serve as a senior adviser to Mrs Clinton and the campaign, and travel with Mrs Clinton from time to time.
Ms Williams will begin assuming the duties of campaign manager this week.
In a statement, Mrs Clinton praised ms Solis Doyle and said she looked forward to her continued advice in the coming months.
“Patti Solis Doyle has done an extraordinary job in getting us to this point - within reach of the nomination – and I am enormously grateful for her friendship and her outstanding work,” Mrs Clinton said.
“And, as Patti has said, this already has been the longest presidential campaign in history and one that has required enormous sacrifices of everyone and our families.
“I look forward to her continued advice in the months ahead,” Mrs Clinton added.