Sargent summarizes a new poll from CBS:

The poll’s toplines find that support for legalizing gay marriage is at 53-39, with a stunning 33 percent of Americans who support marriage equality claiming they once held the opposite view. That alone underscores how fast the culture is changing on this issue. And here’s another key tidbit underscoring cultural movement: There is a sharp generational divide among Republicans on the issue. Overall, 56 percent of Republicans oppose legal gay marriage. But I asked the CBS polling team for a breakdown by age, and the result was that among Republicans under 50, a plurality of 49 percent supports legalizing gay marriage, versus only 46 percent who oppose it.