I just thought you might be interested in these charts by the Pew Research Center on approval of same-sex marriages in the United States. They come from a survey done between June 8th and 18th of a random national sample of 2,504 adults, with a 2.3 point margin of error.
It shows that approval is not just growing among the public at large, but is also growing among all groups in this country (even groups that still disapprove).
