In I am America (And So Can You!), Stephen Colbert mentions an ASR piece. I'm too lazy at the moment to look up the citation or to even quote the relevant passage from the Colbert book, but, it's in the chapter on religion, where he is discussion atheists.
He mentions the Edgell et. al study published in the American Sociological Review which indicates that atheists are the most socially disliked group in the U.S.