For the scariest reason imaginable - they've got nobody left. The best they could do is Huntsman and he's unelectable to them. Paul and The Glove are the next with Glove being the most likely to have a chance. The religinuts back Frothy because they love him the best. It's like voting for the 500+:1 odds horse/boxing match, or using your car and a rope as a penis enhancement tool. If you get lucky, it doesn't matter that it'll never work again in a million years, it doesn't have to.
They just have to set their cards up right to get Frothy to win this once, and America's fucked.