Cam, the 1st amendment is about the gov not making any church or religion the official state religion. It means you can't force people to tithe or endorse one faith or another in order to hold office. Its also about the protection of worshipers of either Jesus or Alah or whomever can do so without government interference. It doesn't mean that if you hold the belief that one faith is more true than another then you cannot serve on as a public figure. That's where Sanders was treading on thin ice. He essentially said "your religion, do you believe it to be more true than others?" and if the answer was yes then he was going to go after him a bit.