When the senior senator from Connecticut stood to give his parting address Wednesday afternoon, just one of his colleagues, Delaware Democrat Tom Carper, was with him on the Senate floor. …

A few more senators arrived during the 20-minute speech, but even by the end Lieberman was very much alone — which is how it has been for much of his 24-year tenure. He tried to push back against the mindless partisanship that developed in the chamber, and he paid dearly for it. …

And so it was a man with few political allies who bid the chamber farewell. “I regret to say as I leave the Senate that the greatest obstacle that I see standing between us and the brighter American future we all want is right here in Washington,” he said. “It’s the partisan polarization of our politics which prevents us from making the principled compromises on which progress in a democracy depends.” …

Lieberman did not attempt to settle old scores Wednesday, and he avoided his trademark sanctimony. He made one last appeal to his colleagues to “support, when necessary, the use of America’s military power” and “have the patience and determination when the public grows weary to see our battles through until they are won.”