Well considering that he’s an Independent Democrat-in-name-only, this would just mean the circle is now complete. The turncoat would make the race quite interesting though. Think about Huckabee and Rick Santorum up there at a debate. (Think Progress):

In an interview, Sen. Joe Lieberman (I-CT) joked that he could potentially run as a Republican

–Some Democrats might not find Lieberman’s joke very funny. After Lieberman bucked his party and supported Sen. John McCain (R-AZ) for president – even delivering a speech at the Republican National Convention – some of his Senate colleagues wanted him to be punished, with some suggesting that he should lose his chairmanship of the Senate Homeland Security and Governmental Affairs Committee. Instead, they let him off with slap on the wrist.

I wonder what kind slogan Lieberman would want to put out there. Could you think up something snappy for him?