I've hung out in left circles enough to know the standard response to such an action (organize some sort of letter-writing campaign or petition urging them to withdraw the invitation); I've also hung out in left circles enough to know such response will not be forthcoming in a case like this. But honestly, I'm okay with that. Why? Because cases like this demonstrate, to me, just how impoverished that response is to those of us victimized when bigotry of this sort is sanctioned.
Suppose that such a campaign was organized, and that Friends did change its mind. What's the result? Well, aside from the inevitable carping and crowing about how "the Zionists" (or "the Jews", since Atzmon tends to at least be more honest than many of his fellows in not abiding by the charade -- if, as Martin Luther King put it, "when you criticize Zionism, you mean Jews", then Atzmon has taken that message to heart in exactly the opposite of how it was intended) have "silenced" him, all we'd have proven is that given enough pressure and bad PR, Friends will not act in an overtly anti-Semitic manner.
But that's not what I want. I don't want Friends to be vulnerable to a pressure campaign. I want Friends to not have invited Atzmon in the first place. I want it to have never occurred to them that it was remotely acceptable for them to allow in an anti-Semitic bigot within their walls. Of course, it's too late for that now -- the key battle has already been lost. So now I want them to, on their own, come to the epiphany that such hatred is wrong, that Jews are equal and valued members of the political community, and to treat us accordingly even when nobody is watching; even when nobody seems to care. I'm not optimistic, but any other "victory" is hollow and without meaning.
If one only has protections because one devotes every spare vote, dollar, resource and minute to secure them, one can hardly be said to be an equal. Equality comes when equality is normal — so normal, that you don’ t have to be perpetually on your guard to defend it. So normal that it wouldn’t occur to anyone to try and take it away.