Timothy Stanley: Is Same-Sex Marriage Too Radical for America?

Timothy Stanley is a historian at Oxford University and blogs for Britain's Daily Telegraph. He is the author of the new book "The Crusader: The Life and Times of Pat Buchanan." This commentary has been updated to reflect President Obama's statement this afternoon.

(CNN) -- President Barack Obama has endorsed same-sex marriage. Will it make any difference to the battle for marriage equality? The news coming out of North Carolina suggests not. The Tar Heelers on Tuesday voted 61% to 39% to amend their constitution to outlaw same-sex marriage. Actually, they've gone much further. The new amendment prohibits any kind of same-sex unions, including the relatively innocuous option of civil partnership....

There's a popular myth that social liberalism is unstoppable. But the tide of progress is a myth. Societies have often taken a step forward only to stand perfectly still or even take a couple of steps back. In hindsight, the journey of black civil rights looks like a brisk jog in a straight line, but it was really a winding stumble. The ecstasy of emancipation was followed by the misery of segregation. And although legal segregation was defeated, some would argue that it still continues....

Given how controversial it is, same-sex marriage could go the way of the ERA -- a reform too far, joining the long list of Democratic, election-time promises that no one ever expects to see realized. And given that he offers no new policies on the subject (he can't: It's a classic states rights issue), Obama's endorsement is little more than kind words. They are brave words in that seven out of the nine swing states he's contesting in November have constitutional amendments outlawing same-sex marriage -- most of them passed by popular referenda. "The folks," as Bill O'Reilly calls middle America, don't like it....