73% of Americans believe in it. And, though this may be a shock to many Americans, so do most Muslims.
As I will discuss in a later post, there are serious historical difficulties with the Virgin Birth--and contrary to what many people might think, the fact that it's a miracle is not the most serious of these historical problems. Intriguingly, however, the tradition of the Virgin Birth, while not historical in and of itself, may actually point to one aspect of the Christmas story that is historically accurate. But more on that in due time.
The overwhelming religiosity of the American public is, of course, striking. But also striking is the overwhelming ignorance about other religious traditions, measured in other surveys. And lack of knowledge about Islam in particular means that almost no Americans know about the extreme reverence that Islam has for Jesus as a prophet (the second greatest prophet behind Muhammad). Yes, Muslims don't consider him to be God incarnate. But they do agree with almost all of the other major Christian truth claims about him, including the Virgin Birth and his miracles. The issue of Jesus' crucifixion in Islam is complex, and maybe we'll save a post on that for Easter.