Just two days after his inimitably voluble vice president kind of, sort of, probably came out in favor of same-sex marriage, and just a day after his education secretary expressed more succinct, unambiguous support for it, Barack Obama is scheduled to visit New York and cross paths with the governor who is arguably the Democratic standard-bearer for marriage equality, Andrew Cuomo.

And it will be clearer than ever: on this issue, the president isn’t leading. He’s following. And the gap by which he trails others in his party grows broader and sadder.

Maybe he’ll surprise us this week. I doubt it, for reasons that I’ll explain shortly — and that I mostly sympathize with.