When Democrats passed the first supplemental, in one week they lost 10% approval ratings. That is, effectively, overnight. If Democrats approve the additional 50 billion (and you know they will) they will be approving money for the war at a faster rate than the Republican Congress was. Remarkable.
The population of the US wants to leave Iraq. Iraqis want the US to leave Iraq. But neither Democrats nor Republicans want to leave Iraq. And that includes "liberals" like Durbin. They simply, objectively, do not wish to do so. We can speculate on the reasons - perhaps they are genuinely scared of being seen as "not supporting the troops" (ie, perhaps they're genuinely chickenshit); perhaps they are scared that George Bush will, if they don't give him money, arbitrarily get soldiers killed for no good reason by refusing to withdraw anyway; perhaps they are so caught up by Washington's elite (and generally wrong) foreign policy establishment and want to seem like reasonable adults to that group of "serious people"; perhaps, even, a few genuinely care about the possibility of genocide and want to stay as a result (though I really doubt most give a damn, Iraqi casualties never having bothered most of them ever before).
Whatever the case is, most of them, as judged by their actions not their words, don't want to end the US's occupation of a foreign country that doesn't want them there.
There are no good guys on Capitol Hill. Whatever party they belong to, they know damn well what the right thing to do is. And they absolutely refuse to do it.1 Why? Because they're scum. No other reason. They are simply stinking, dickless cowards who intentionally refuse to stand in the way of this generation's Vietnam.
And you elected these people. Some of them, you elected twice. Remember that. You are just as complicit as everyone else.
1 Single exception AFAIK: Ron Paul. But 1 out of 535 is not even 1%. Hell, it's not even two-tenths of 1%. We'll get Ron Paul out before the nukes fall on DC. Everyone else, to a man, can burn. The goddamn shitheads.