I am amazed it is an issue.
Clearly many religious leaders in the US are immoral people, whose main purpose appears to be to lead other people with no wits about them to provide them with a fortune.
People who follow such leaders are called Christians. But they aren't virtuous because of it. Indeed, they are usually very unthoughtful about moral issues. For instance, they will pretend to care about foetuses to the point of sanctimony; and yet they don't care a damn for children separated from their parents at the border. We have learnt that already in the American public conversation.
The problem, of course, is partly that Christians depend upon a book with vacillating ideas of morality. Christian leaders can take advantage of this to justify everything from genocide to torture to slavery to invasion. Or they can excerpt verses from it to convert the image of an obvious conman into that of a saint. And in the usual way, there's a flock for every position a Christian leader takes.
I wouldn't rule out religious people from office. But I'd certainly question whether their beliefs interfere with the performance of their political duties in a secular democracy.
Non-believers have the benefit of thinking the natural world and a balanced sense of morality formed within crucible of the evolved conscience of humanity (without giving a trump power to a bronze age book) are the things to invest in.