Americans revealed their ambivalence on gay marriage in a new poll, with a narrow majority of people surveyed saying the government should recognize same-sex marriage but nearly half supporting a constitutional ban on gay marriage.

A nationwide telephone poll of 1,000 adults found that 53 percent believe the government should accord legal benefits to same-sex married couples, about the same proportion as last year and a notable shift from 2009, when a slim majority of Americans were opposed. However, 48 percent of people surveyed supported a constitutional amendment defining marriage as between a man and a woman, which would effectively bar gay marriage.

The deep divide reflects the fitful and uneven evolution of views on gay marriage, which vary between different regions and age groups. About 55 percent of respondents said states should decide the issue, compared to 39 percent who said it should be the federal government's purview. That view paralleled the different legislation emanating from state capitols: in June, New York became the sixth state to allow same-sex marriage, while North Carolina voters will decide next May whether to bar legal recognition of same-sex relationships.

Currently, the Defense of Marriage Act prevents the federal government from recognizing same sex marriage. That means gay couples who marry in states that have legalized same-sex marriage are eligible for some benefits but still are denied over 1,000 federal benefits that include Social Security privileges and upgraded immigration status for spouses.