Maybe a better term, then, would be "theists." And most theists in the US are Christian, yes.

The issue here seems to be not whether someone believes in a supreme being, or even the Christian one; but whether they believe in a particular religious ideology that includes a literal reading of a holy book, which is at odds with scientific evidence and theory. If you deny the reality of the evidence and theory, and you are a scientist, then there's a problem.

There are other creation stories from cultures around the world. Some talk of original gods dividing themselves up to make other gods, and then people. Some talk of the gods fashioning people from clay and then bringing them to life. According to the Iriqois,the Sky Woman oversaw the making of the earth while she sat on a turtle; the turtle holds the earth up to this very day.

If a scientist claimed that their holy book told them the earth was held on the back of a turtle, so therefore it must be true, I would have serious problems with trusting them to be doing objective science. I would have the same problems with a scientist claiming that the earth is young and that all living things on the earth were created concurrently.