The graph on the left (right), where the lines cross, is a familiar one for anyone following the gay and lesbian movement. More recent polls show support for same sex marriage as high as 58 percent–although, as marriage equality opponents note, turnout matters a great deal.
The generational break-down, at the right of the figure, should also be fairly familiar. Younger people are far more likely to support same sex marriage. This bodes well for the gay and lesbian movement over time. Both same sex marriage supporters and opponents will be getting older over time; more of the opponents will, uh, no longer be engaged in the political debate.
But it’s not just generational replacement.
Pew also asked people who have changed their minds why they did so. Although you should always take such results with more than a grain of salt, the most common explanation for shifting to support marriage equality was knowing a gay person.
When more people come out as gay or lesbian, or as the friend or relative of someone gay or lesbian, fewer people will be able to avoid knowing a gay person.
A little coda: popular culture matters here. American television viewers know Ellen DeGeneres or those sweet snarky fellows on Queer Eye for the Straight Guy. The friendly folks on television may spend more time in your living room, sort of, than any of your neighbors.
When GAY seems less odd, it’s increasingly difficult to justify discrimination.