Okay, so, to make a long story short, the Lieberman campaign has been resorting to openly goonish tactics of late: heckling, bullying, physical intimidation, and even violence. I can only assume that they're trying to rattle Lamont or his supporters into some kind of embarrassing, discrediting retaliation.
But here's the thing: Joe has spent at least 18 years cultivating his image as a gentleman. Someone who (I think) a lot of people consider a good and decent man, even if they don't agree with him politically all the time. He is now in the process of pissing away the very last dregs of that goodwill.
Morality and decency (or at least the appearance thereof) have been a big part of Lieberman's persona and political staying power, but now he's playing the thug. Good luck with that, Joe - I wonder if anyone will ever refer to you as "that nice Mr. Lieberman" ever again.