At Five Thirty-Eight.com, Nate Silver has a chart showing a correlation between same-sex marriage bans and divorce. It’s not a perfect correlation, but as you can see, states that have gone to the trouble of banning same-sex marriage, and in particular when it’s banned by constitutional amendment rather than merely by statute, tend to have higher divorce rates.
And the state with the highest divorce rate, Alaska, also was the first to add a same-sex marriage ban to its constitution, in 1998. Heh.
Maybe the secret to a happy marriage is to marry a gay Buddhist.