Dunking: This seems like the second-best option for Trump after the Prayer Test. All he would need to do is strip down to his undergarments and then allow someone to throw him into a large body of water with a rope tied around his waist. (I believe former FBI Director James Comey would be a good candidate to do the Trump tossing.) Per the History Channel: “Since witches were believed to have spurned the sacrament of baptism, it was thought that the water would reject their body and prevent them from submerging.” If the president floats, he’s a witch. If he’s not a witch, he would sink like a stone and Comey would pull him back up. Hopefully.