Ben Carson’s campaign manager Barry Bennett, Deputy Campaign Manager Lisa Coen, and Campaign Communications Director stepped down from their posts with the presidential campaign Thursday morning:

[…] “We respect the candidate and we have enjoyed helping him go from far back in the field to top tier status,” Watts said of himself and Bennett in a statement Thursday. “We are proud of our efforts for Dr Carson and we wish him and his campaign the best of luck.”

The resignations, reported first by the Des Moines Register early Thursday, come just 31 days before the Iowa caucuses.

Of the decision to leave the campaign, Bennett told the Washington Post, “My frustration level has peaked with Dr. Carson’s outside advisers.” (link)

It appears the key “outside adviser” creating the internal anxiety amid the campaign is Armstrong Williams.  That should not come as a surprise – Remember this.

ABC News has more –  After announcing his resignation from the Ben Carson campaign, former campaign manager Barry Bennett tells ABC News that the staff changes were revealed in a scheduled call this morning. The main change Carson wanted to make was with his Communications Director Doug Watts, Bennett says.

Bennett told the Republican presidential candidate on the call he would not support that decision and told Carson “it’s time for me to go.” Bennett said Carson was surprised and asked him to think about staying on as his campaign manager to which Bennett quickly told him no.

“[Carson] tried to blame some of the problems in the campaign on silly things and I said Ben we all know the root of our problems, let’s not pretend it’s not Armstrong Williams,” Bennett told ABC News on the phone. “Ben said I’ll talk to him, I’ll talk to him. But I’ve heard that for nine months now.”

Williams did not immediately respond to ABC News’ request for comment.

Bennett said he’s leaving the campaign with lots of money in the bank and still believes in Dr. Carson as a candidate.

“I don’t know who all will still be here, it’s not my problem” Bennett said. “I can play amateur politics at home with my 9-year-old I don’t need to do it at the professional level.”

The campaign says that Armstrong Williams was “the factor” of the staff shake-up. Williams is Carson’s business manager and one of his closest advisers who has been with him long before he launched his campaign.

Throughout Carson’s campaign, conflicting messages have come from Armstrong and the campaign, and the campaign acknowledges that Armstrong created a huge problem. Campaign Manager Barry Bennett told ABC News on Dec. 11 that the relationship was “a disaster.”  (read more)