There's an elite club among Harvard students and alumni called the Owl Club. Harvard kicked them off campus for not allowing women to join. The membership of this organization includes Senator Ted Kennedy. The Owl Club has been criticized regularly as sexist and elitist. Some of the things said about this club are probably as unfair as the many mischaracterizations of Concerned Alumni for Princeton. If Dinesh D'Souza could be a member of the latter group, then I'm not going to criticize Ted Kennedy for being a member of the former. What I can criticize Kennedy for is his McCarthyesque line of questioning against someone who by all accounts was at most incidentally connected with an organization that at worst has some members willing to say bad things (and it's not clear how much of that was intended satirically; see the D'Souza interview for more on that) and a magazine with low standards for what it publishes. But read the whole Owl Club article for signs of that with Kennedy's own club.
So it turns out that Senator Kennedy isn't just grossly misrepresenting the views and practices of a group that Alito barely had any connection with as a way to McCarthyize Alito. He's doing so from the perspective of someone who has active membership in a group that could just as easily have the same sorts of things said about it (rightly or wrongly). You don't even need to get into Kennedy's past (and he did acknowledge in the hearings that he's made his share of mistakes) or his womanizing reputation (which if accurate should disqualify him from making any moral claims against anyone else for how they treat women). I'm not normally about trying to drudge up details of people's private lives to reflect their character, but when a public figure misrepresents and impugns the record and character of someone who looks to me to be an upstanding man and judge, I can't help but point out that the same ridiculous argument could just as easily apply to the person making it. His very making of the argument invites the comparison, and in this case it's at least close to apt.