In this Oct. 29, 2015 file photo, Republican presidential candidate Ben Carson speaks in Lakewood, Colo. For some Republican presidential candidates, the party’s first three primary debates have been pivotal proving grounds that have strengthened their campaigns or shaken their supporters. The famously mild-mannered Carson has largely avoided making headlines in the widely watched televised events, often willing to cede the spotlight to more verbose rivals. Yet the retired neurosurgeon’s standing with voters in preference polls has only gotten better. (AP Photo/David Zalubowski, File)

Carson staffers quit, question his readiness for White House

Stepped down with less than five weeks before voters in Iowa begin the nominating process with the state’s Feb. 1 caucuses.