Meanwhile, respondents split about evenly on whether gay-marriage laws should be decided on the state or federal level. Just under half — 49 percent — of those surveyed said marriage should be a state issue, while some 46 percent believe the federal government should decide. Proponents of gay marriage tend to support federal legislation, a likely reaction to voters in 30 states deciding against same-sex marriage.

The survey seemed to validate previous polls that suggested the president's announcement would not play a major role in the campaign, with most saying it would not sway their vote for president. Those who felt passionately about the issue were virtually split between opposition and support for the president's position.

The poll also found that Americans are increasingly aware of their personal connection to someone who is gay. More than 7 in 10 of those surveyed said they had a friend, family member, or acquaintance who is gay, up from 63 percent in 2010 and 59 percent in 1998.