Here’s a shocker. Now that Barack Obama has endorsed same-sex marriage, the polls are moving abruptly in that direction:

Public opinion continues to shift in favor of same-sex marriage, according to a new Washington Post-ABC News poll, which also finds initial signs that President Obama’s support for the idea may have changed a few minds.

Overall, 53 percent of Americans say gay marriage should be legal, hitting a high mark in support while showing a dramatic turnaround from just six years ago, when just 36 percent thought it should be legal. Thirty-nine percent, a new low, say gay marriage should be illegal.

The poll also finds that 59 percent of African Americans say they support same-sex marriage, up from an average of 41 percent in polls leading up to Obama’s announcement of his new position on the matter. Though statistically significant, it is a tentative result because of the relatively small sample of black voters in the poll.

Leadership generates its own support for policy.

Hopefully, this lesson will stick, but I doubt it.