Only 34.7 percent of those surveyed by the Field Poll said they disapprove of same-sex marriage, while 59 percent approve. Another 7 percent said they do not have an opinion.
When the Field Poll first asked about gay marriage in 1977, 59 percent disapproved and 28 percent approved. In 2010, just over half, 51 percent, favored gay marriage and 42.7 percent disapproved.
The survey found the only identifiable groups definitively opposed to gay marriage are Republicans and those describing themselves as conservatives. Majorities of Democrats, independents, Catholics, members of non-Christian faiths and non-Hispanic whites all said they favor same-sex marriage, while blacks, Hispanics and Protestants were split.
The Field Poll surveyed 1,003 registered voters Feb. 2-18. The margin of error is 4.5 percentage points.