Donald Trump 's latest work of demagoguery -- a proposal to ban Muslims from entering the U.S. -- doesn't seem to have hurt his standing in the polls. But is the idea completely out of the mainstream?

Four new surveys this week -- from YouGov , NBC News/The Wall Street Journal , CBS and Bloomberg Politics/Purple Strategies -- asked about the ban, but didn't do much to clarify things, showing everything from widespread opposition to a nearly even split.