While I would, indeed am not now, comfortable with a Muslim POTUS, has Carson even read the Constitution and no religious test for office. Statements like Carson’s were commonly made about preventing Catholics from holding office, citing their supposed allegiance to Rome. I’m sure that some on FR still hold that view.
And yet there’s not one Protestant on the supreme court as all of our forefathers were. FU.
Carson's statement demanding candidates take an oath on a "stack of bibles" wouldn't prevent any Catholic taking from office, however it DOES fly in the face of the "no religious test" section of the constitution and would prevent numerous religious denominations that oppose oaths on bibles from taking office.
Most prominent would be Mennonites and Quakers (both faiths oppose having their members swear oaths on bibles). Many devout Jews would also object to taking an oath of office on the new testament, and prefer to use a torah instead.