Rob Tisinai identifies one reason various conservative politicians are suddenly voicing their support for marriage equality:

Imagine you’re a conservative. And you support marriage equality. And you’ve been silent. But now you realize this may be your last chance to say you supported same-sex marriage before it becomes the law of the land. How mortifying must it be to know you sided the angels with the great civil rights struggle of our day, but that no one will ever believe you?  To know you’re on the right side of moral history, but might be seen for the rest of your life as one of its opponents? To know you believe in the American ideals of freedom and human dignity, but sat out this historic struggle to turn America into a more perfect union?

How mortifying must it be to know you are right, but your silence now could brand you forever as having been deeply and morally wrong?