Obama announced last year that he personally supported gay marriage, making him the first sitting president to do so publicly. Republican presidential candidate Mitt Romney said repeatedly on the campaign trail that he supported only the traditional definition of marriage.
The national poll also seems to closely mirror attitudes in the four states that considered gay-marriage ballot initiatives last week. In Maine and Washington, voters broke in favor of legalization by 53-to-47 percent margins. In Maryland, voters approved same-sex marriages 52-38 percent; Minnesota rejected a constitutional amendment that would have defined marriage as between a man and a woman, 51-48 percent.