Hasn't been so far, but then they said a Catholic couldn't be elected until JFK broke that barrier.  I'm surprised Joe Lieberman didn't run, given his high national profile and centrist almost non-party positioning.  Perhaps his private polls were telling him he didn't have a chance in a Democratic primary season where Iraq was such a negative issue...

"It's a mystery to me - the game commences, For the usual fee - plus expenses, Confidential information - it's in my diary..."