That's the party designation that Connecticut Senator Joe Lieberman has applied to himself, ever since the general election of 2006, in which he defeated Ned Lamont, the man who had beaten Lieberman in the Democratic primary.
But how independent is he?
The word on Lieberman has consistently been that, while he's a hawk on foreign policy, he toes the Democratic Party line on domestic issues.
Apparently, with some exceptions.
Nate Silver, in the 538 blog, points out that Lieberman is taking a stand that is further to the right than the rest of his party, regarding health care legislation. Silver makes a plausible case that that won't help Lieberman's reelection prospects next time, as a Democrat, an Independent, or anything in between.
My opinion is that a legislator's motives for anything he or she does or says, are some mixture of 1) what he or she thinks is right; and 2) what will help him or her get reelected.
Some politicians will claim that it's all based on that first motive. On the other hand, the most cynical of observers will maintain that the reelection motive is all there is. But I think it's always somewhere in the middle.
To the extent Lieberman may think that his health care stand will help him win reelection, I agree that he has miscalculated.