John over at AmericaBlog has an interesting theory on Reid’s support for McCain’s troop increases:

Reid may be using the troop increase as a backdoor way of getting a firm commitment to end our combat engagement in Iraq by 2008. By giving our commanders on the ground what they want - if in fact they want more troops - Reid and the Democrats are seen as supporting our commanders rather than undercutting the war effort, and ultimately being blamed by the Republicans for losing the war. But at the same time, Reid is giving our generals, and our commander in chief, one last change to fix things. And if they don't, we're out of there - the public will know that Bush has lost this war, Harry Reid gave him a fair shot, and it was the Democrats that finally got our troops home safely.

Intentional or not, the trajectory seems to indicate that this is what’s panning out in the Senate. The question is whether Reid is going to have the influence to push this through with proper controls.