Other than (arguably) the resignation of Alberto Gonzales as attorney general and a very modest increase in the minimum wage (enacted in the first month after Democrats took control of Congress), one is hard-pressed to identify a single event or issue since November 2006 that would have been meaningfully different had the GOP retained control of Congress. The Congress of Harry Reid and Nancy Pelosi has been every bit as passive, impotent and complicit as the Congress of Bill Frist and Denny Hastert was. Worse, in contrast to the Frist/Hastert-led Congress, which at least had the excuse that it enabled a wartime president from its own party while he enjoyed high approval ratings, the Reid/Pelosi Congress has capitulated to every presidential whim despite an "opposition party" president who is now one of the most unpopular in modern American history. It's difficult to imagine how even Reid and Pelosi themselves could contest the claim that the Democratic-led Congress, from the perspective of Democratic voters, has been a profound failure.
With those depressing facts assembled, the only question worth asking among those who are so dissatisfied with congressional Democrats is this: What can be done to change this conduct? As proved by the 2006 midterm elections -- which the Democrats dominated in a historically lopsided manner -- mindlessly electing more Democrats to Congress will not improve anything. Such uncritical support for the party is actually likely to have the opposite effect. It's axiomatic that rewarding politicians -- which is what will happen if congressional Democrats end up with more seats and greater control after 2008 than they had after 2006 -- only ensures that they will continue the same behavior. If, after spending two years accommodating one extremist policy after the next favored by the right, congressional Democrats become further entrenched in their power by winning even more seats, what would one expect them to do other than conclude that this approach works and therefore continue to pursue it?
Kilgore's response was pretty flaccid, so rather than quote him I think commenter to Greenwald's post Diomedes makes the better counter-argument:
Greenwald seems to me to be reflecting the attitude of many left-wing progressives, but I think it much more appropriate to remember that the voters in these congressional districts knew they were voting in conservative Democrats, liked it that way, and probably wouldn't go for a liberal if one had been offered.