Here you go;
Half of Americans Support Legal Gay Marriage
Democrats and independents in favor; Republicans opposed
by Frank Newport
"PRINCETON, NJ -- Fifty percent of Americans believe same-sex marriages should be recognized by law as valid, with the same rights as traditional marriages -- down slightly from 53% last year, but marking only the second time in Gallup's history of tracking this question that at least half of Americans have supported legal same-sex marriage. Forty-eight percent say such marriages should not be legal"
I can not post the link as that requires a minimum of 100 posts, but if you Google " Gallup gay marriage" it will take you to the website.