Just a little over a decade ago, a majority of Americans opposed allowing members of the same sex to marry. But in the last 12 years or so, there's has been a radical change in the public's opinion.
Currently about two-thirds (67%) of all Americans support allowing same-sex couples to legally marry. Only 31% don't want the law (and the Constitution) to apply to everyone. Even half (49%) of Republicans now support marriage equality -- along with 71% of Independents and 83% of Democrats.
The charts above are from the Gallup Poll -- done between May 1st and 13th of a national sample of 1,028 adults, with a 4 point margin of error.