After the sadness of California passing Proposition 8 banning gay marriage last year, there have been a couple of recent victories for civil rights campaigners in Vermont and Iowa. That motivated Nate Silver to work the numbers and ask when we might expect the rest of the US to reject a ban on gay marriage. The outcome is shown in the following diagram from The Map Scroll:
The regression that Silver used achieved an R-squared of 0.75, which is pretty incredible, and contains three variables:
- The year in which the amendment was voted upon;
- The percentage of adults in 2008 Gallup tracking surveys who said that religion was an important part of their daily lives;
- The percentage of white evangelicals in the state.
The latter two make sense, since many religious peole interpret their religious text as prohibiting gay marriage. The first variable seems a strange one to be significant. I guess it’s possible that Americans are just becoming more liberal (that goes out to you, goonix), but the party registration data wasn’t significant which suggests otherwise. Are young Americans, who are usually more liberal, more likely to vote these days? I don’t know the numbers but I would guess not. Does anyone have a plausible explanation? I suppose the most convincing (and least falsifiable) one that I can think of would be that the entire US political spectrum has shifted, such that gay marriage is more acceptable to Republicans and Democrats alike.]