As Mike noted the other day, Joe Biden has been telling everyone that it would be "constitutionally questionable" for Congress to write a bill preventing the White House from sending more troops to Iraq. The most Democrats could do, he said, is draft "a resolution of disapproval."
Except, as Marty Lederman pointed out on Sunday, Biden's quite wrong about this. Democrats could very easily write a bill that prohibited Bush from sending in more than a specified number of troops to Iraq. Or they could require that any extra troops be used only for certain purposes, or only for a certain length of time. It's all perfectly constitutional, and there's plenty of precedent for this. (Neil Kinkopf has a similar analysis here.)
Now granted, even if Democrats did pass legislation along those lines, it would almost certainly get the business end of a White House veto. And perhaps Democrats really would suffer politically if they tried to do this, even though the current escalation is opposed by most voters. Maybe there's some other, more effective way to bring the Iraq war to a close. (Although if Democrats are just hoping, like John McCain apparently is, that the war will wind down on its own, they could be twiddling their thumbs for a long, long time...)
Still, it seems that Biden's wrong to claim that Congress' hands are completely bound. In any case, this seems like a rather odd time for key congressional Democrats to be taking a dim view of their own institutional powers, no?