On the fourth anniversary of the day of the Iraq War Resolution vote in the run-up to the last round of midterm elections, it's important to remeber the particularly destructive role Sen. Lieberman played in making sure the resolution was as vague as possible - and making sure President Bush had as much of a blank check as possible to avoid accountability later on.

RJ Eskew in the Huffington Post states it clearly:

The Iraq War might already be over if not for Joe Lieberman. Now, as Connecticut's voters prepare to go to the polls, they should remember how this self-described "moderate" helped kill concerted efforts by true moderates of both parties to limit the President's war-making power.

Lieberman played a key part in crushing the bipartisan Biden-Lugar amendment to the Iraq War Resolution.

That amendment would have limited the President's war-making role to eliminating Hussein's WMD capabilities - a limitation which would have required the President to seek further authorization once it was known that Saddam had no WMD's.
The Senate might well have refused that authorization. At a minimum, few Democrats would have supported a second authorization. That would have given them a much clearer story for the 2004 election, and probably ensured a Kerry victory.

It would also have required the President to return to Congress with further documentation that he had pursued action in the UN Security Council, and to certify that he had clear proof of an immediate and grave threat from Iraqi WMDs.

The Biden-Lugar amendment was supported by true moderates of both parties, including key Republicans like Dick Lugar and Arlen Specter. Supporters from both sides of the aisle were convinced it could win 60 to 70 votes - that is, until Joe and his friends stepped in.

One day Lieberman and Dick Gephardt (representing sell-outs from the Senate and Congress, respectively) appeared with Bush in the Rose Garden to announce that they support the War Resolution as is - without Biden-Lugar. Support for the Amendment collapsed overnight.