Last year, public dissatisfaction over the ongoing slaughter in Iraq saw the Democrats sweep to power in the US House of Representatives in one of the biggest landslides in US political history. Now, they're doing what they were elected to do, by setting a deadline for withdrawal from Iraq. The President is blustering and threatening a veto, but the deadline is in the very bill funding the war - meaning that if it is vetoed, the troops don't get paid. So instead he'll have to twist arms in the Senate, and then expend precious political capital (a declining resource in a lame duck administration) trying to kill the clause in conference committee. And even then, the Dems can stall, and drag out the clock unless they get their way.
We may be about to see some very high-stakes political chicken in Washington. The question is whether the Democrats have the spine for it, or whether they will betray the voters who elected them last November.