Actually, support for same sex marriage is pretty even among all ethnic groups in the US.
I think I would be careful here. Read the caveat:
“The poll also finds that 59 percent of African Americans say they support same-sex marriage, up from an average of 41 percent in polls leading up to Obama’s announcement of his new position on the matter. Though statistically significant, it is a tentative result because of the relatively small sample of black voters in the poll.”
As usual, N is very important.