The presidential candidacy of Ben Carson, a tea party star who has catapulted into the top tier of Republican contenders, has been rocked by turmoil with the departures of four senior campaign officials and widespread disarray among his allied super PACs.

In interviews Friday, Carson's associates described a political network in tumult, saying the retired neurosurgeon's campaign chairman, national finance chairman, deputy campaign manager and general counsel have resigned since Carson formally launched his bid last month in Detroit. They have not been replaced, campaign aides said.