Lonelier than Estes Kefauver at a meeting of Murder Incorporated!

So, I saw this on the Simpsons, and it didn't make any sense at first, but it still doesn't, so I thought that I would put it on here so that people who were wondering can be puzzled with me. So anyway, in this episode, Grampa "Abe" Simpson says the quote that's my title and I went to the Wiki article about Estes Kefauver, and still had no idea why he would be lonely at a convention of murderers. I mean, wouldn't most normal people be lonely there? He seemed like a decent guy, but why not MLK or Ghandi or something? He hated organized crime, so maybe that had something to do with it, but I feel like this reference was a little to obscure for even me. And Wikipedia.