Let us contemplate the badness of Joe Lieberman.

Who would have thought that this holiday season we’d be obsessed with the senator from Connecticut? Really, I was hoping it would be more about shopping for mittens on the Internet.

Lieberman’s apparently successful attempt to hijack health care reform and hold it hostage until it had been amended into something that liberals couldn’t stomach has mesmerized the nation’s political class. This was, after all, a guy who has been a liberal on domestic issues since he was a college student campaigning for John F. Kennedy. A guy who was in favor of the public option, of expanding Medicare eligibility, until  last week.

The theories about Why Joe Is Doing It abound. We cannot get enough of them! I have decided to start a rumor that it all goes back to the 2004 presidential race, when Lieberman not only failed to win any primaries, but was also bitten by either a rabid muskrat or a vampire disguised as a moose.

Other than that, my favorite explanation comes from Jonathan Chait of The New Republic, who theorized that Lieberman was able to go from Guy Who Wants to Expand Medicare to Guy Who Would Rather Kill Health Care Than Expand Medicare because he “isn’t actually all that smart.”