Carson was rivaling Donald Trump for the lead in the Republican presidential race in mid-October, but he has since fallen to 10% in the latest CNN/ORC poll, which ties him for a distant third place with Marco Rubio, behind Trump and Ted Cruz.
His campaign has been marked of late by rumors of personnel changes
and public sniping
between Bennett and Watts with Armstrong Williams, Carson's business manager and sometimes public surrogate who has no official role in the campaign. Williams has criticized Bennett and Watts for not adequately preparing the candidate for public appearances, especially on foreign policy, an issue that has dominated the race in recent months.
Questions about the veracity
of Carson's compelling personal story, about his rise out of poverty in Detroit to become perhaps the nation's most widely known neurosurgeon, have also hounded him as he fell in the polls.
Bob Dees, a foreign policy adviser to Carson, is now the campaign chairman. Ed Brookover, a senior strategist, will be the new campaign manager, Carson's National Finance Chairman Dean Parker said on CNN. Carson's Iowa state director Ryan Rhodes said he will remain with the campaign.
Carson said the move was needed to jumpstart his campaign.
"As we enter a new phase of the campaign cycle, it is necessary to invigorate my campaign with a strategy that more aggressively shares my vision and world-view with the American people," Carson said in a statement. "I commend Barry Bennett and Doug Watts for their efforts to help me share my vision for America. Over a year ago, hundreds of thousands of Americans encouraged me to listen to the call and seek the office of president of the greatest nation the world has ever known. I am ready to be president and believe that my unique experience and background is what is needed to heal, inspire and revive America."
Williams: "Burden" lifted
Williams said Carson has had a "burden" lifted from him with Thursday's announcement.
"What Dr. Carson has to do, which he's doing now, is getting on message," Williams told CNN's Jim Sciutto on "The Lead with Jake Tapper." "He's had a major burden lift for him today. He's made the changes that he's spoke about. He's put in place a new team, and Dr. Carson's marching forward" he said. "He's on message, he's confident. I've never seen him more relaxed, more authoritarian and more in control. And that is good news as we go into 2016."
In an off-air interview with CNN, Williams said he never discussed the personnel moves with Carson.
"It was never Dr. Carson's intention for Barry to resign. The organization was changing and he was unaccepting of the change," Williams said. "And he chose to resign."
Armstrong said Dees' foreign policy experience is a "bonus, but he is also a manager who knows how to get the most out of people."
Despite the rancor, Carson's campaign has raised more than $23 million
in the fourth quarter of 2015, his campaign said Wednesday, although it would not say how much cash it has on hand.
Watts, in a statement, said, "we respect the candidate and we have enjoyed helping him go from far back in the field to top tier status," later adding, "we are proud of our efforts for Dr. Carson and we wish him and his campaign the best of luck."
But Bennett and Watts have been unhappy with Williams' role with Carson, especially as Williams publicly criticized the campaign's struggles, such as the Republican Jewish Coalition speech where Carson repeatedly mispronounced the name of Palestinian group Hamas
"His campaign has to do a better job at preparing him," Williams said in an interview with CNN earlier this month. "Don't give him speeches at the last minute. It's not only on him, it's on them."
Responding to those comments, Bennett said of Williams: "I don't think he is always helpful. You always defend your candidate."
Carson last week pushed back against reports a campaign shakeup was imminent, although he did not discount the possibility.
"The key word there is 'may.' We're always going to be looking at it. We're always going to be evaluating how people are performing" Carson told CNN's Don Lemon
. "No one is ever 100% guaranteed that they're always going to be there."
The resignations were first reported Thursday by the Des Moines Register.