Did they poll these people outside of a Catholic church or what? Sorry, I ain't buying this poll.
Anyway, I haven't a clue what your getting at with your statement. Are you saying the 21% of non-believers in a virgin birth is too high? I would say you widely over-estimate the Christians in the US if you do.
Get me a turkey baster and a C-section in 9 months and I too could show you a "virgin birth" in the 21st century...
It is never to late........