Kevin Drum makes the point (based on some preliminary calculations from Josh Chafetz) that the FMA has a pretty slim, at best, chance of passing and therefore Bush's support of this amendment is nothing more than a political maneuver.
Tell us something less obvious right?
Kevin points out the obvious drawbacks that will come Bush's way for supporting this measure, not the least of which would be losing a major vote in Congress on the eve of an election. Unless, of course, they somehow find a way to delay it until after November. What a nice bill for a lame duck session this would make!
But doing that, or losing the eventual vote, would hurt Bush as well with the very people he is trying to hold in his hands. The extremists, anti-gay agenda right-wingers. These people simply won't accept a half-assed push for the FMA nor will they abide by a defeat of the measure wants it comes to a vote. They will, in turn, be horrified at the prospect of the gay movement in this country being strengthened by a defeat of the FMA and will turn against Bush as the obvious loser of this all important fight.
(Aside: As I understand it, some groups in Massachusetts are actually stymieing efforts to pass a "friendlier" amendment to that state's constitution for precisely this reason. Defeating a really bad amendment would be better for gays then allowing a less odious amendment to pass into law.)
It's hard to see where Bush comes out a political winner in this battle. Surely Karl Rove has to know how dangerous this gambit is. Which brings up the obvious question of why they are doing it now. The obvious answer is that they don't have any other choice. The consequences for them not doing it, despite the dim prospects of them seeing any political benefit from it, are less than doing nothing at all.
In other words, Rove has done the number crunching and thinks that Bush is in serious danger of not just losing but losing big.
This could turn out to be the mother of all hail-mary passes.