“I don't recall that glorious document [the Declaration of Independence] saying anything about all straight men are created equal. I believe it says all men are created equal.”
-- Denzel Washington in the 1993 movie “Philadelphia.”

Social conservatives were intent on winning the political battle over same-sex marriage, and for decades did so with remarkable success. With public opinion massively on their side, it was easy for traditionalists to get politicians of both parties to expand and enforce restrictions of the practice.

But while opponents were racking up wins in Washington and state capitals using public sentiment to their advantage, proponents were trying to change public sentiment itself.

Guess who won?

The Supreme Court has today allowed that states can continue to block same-sex unions but those couples joined in states that allow them will have to be recognized by the federal government.

The discussion today will be all about the politics of same-sex marriage, but that issue, which has proved quite useful to Democrats as a wedge issue in the past three election cycles, is nearing the end of its usefulness with the high court’s decision. Republicans used it to their benefit for many cycles before that, but there are now diminishing returns for both parties.

Advocates of governmental support for those in relationships with members of the same gender have, after a decades-long cultural and political push, mostly exhausted centuries of resistance.

Like the members of the temperance movement before them, prohibitionists of same-sex marriage have been overwhelmed by an increasingly permissive culture that now finds a powerful ally in government. The government, which was once the friend to same-sex marriage opponents, is now playing for the other team.

Successfully branded as prudes, killjoys and moralizers, proponents of traditional marriage now suffer with the knowledge that while many Americans still agree with them, a shrinking number are willing to say so publicly....