Gallop reports On Social Ideology, the Left Catches Up to the Right "Thirty-one percent of Americans describe their views on social issues as generally liberal, matching the percentage who identify as social conservatives for the first time in Gallup records dating back to 1999."
Lots more graphs in the post.
Kevin Drum comments, "What's interesting about this is that the change is due almost entirely to Democrats and Democratic leaners. Since 1999, that group has gone from 35 percent socially liberal to 53 percent, and from 20 percent socially conservative to 14 percent conservative. Republicans and Republican leaners, by contrast, have barely budged."