I was once asked if there was "any criticism of Israel that you wouldn’t automatically suspect of anti-semitism." I took exception to the premise of the question (as I felt quite within my rights to do), but noted that it also missed the point. The mistrust tends to be directed more towards critics than towards criticisms.
[M]y presumptions, if you will, are not tied merely to the statement but also to the stater. A comment, issued by someone whom I know and respect and know cares about Jews and truly views and treats them as equals (particularly if they themselves are Jewish because then it’s their body on the line) is going to meet more acceptance than the same comment by someone whom I know is an anti-Semite (and of course there is a continuum in between). So J Street won’t meet with charges of anti-Semitism from me even when I disagree with them, because I know they are committed to norms of fairness as well as the security of Israel and Jews. By contrast, [my] default stance towards Sudanese President Omar al-Bashir is significantly more … skeptical.
The problem, of course, is that in the whole wide world I don’t know most people, and thus don’t have access (at least at first glance) as to whether they are people who truly view Jews as equal, understand Jewish history, value Jewish perspectives — in short, are allies. My default assumption is that they are not. I don’t think that’s unreasonable of me — it certainly accords to my experience with most non-Jews I’ve met who don’t really know that much about Jews qua Jews (this is true for pro- as well as anti-Israel folks out there).
That isn’t to say that I believe the average person is a Jew-hating Nazi; I don’t. I just don’t have any particular reason to believe that Joe Random Gentile either knows all that much about or cares all that much about Jews, beyond mainstream stereotypes. In a world where this is the default, I’ll admit to starting off mistrustful unless I see indications otherwise. Show me you value Jewish perspectives, show me that you think Jewish bodies matter, show me you take as seriously as human beings and not as caricatures or objects, and you’d be surprised how far I’m willing to walk with you.
In a world of limited knowledge, we have to use heuristic short-hands when trying to evaluate the motivations and intentions of political actors. Suppose I overheard a stranger railing vitriolically against affirmative action. Now, there are plenty of grounds by which to critique affirmative action from an avowedly anti-racist perspective. Nonetheless, my immediate assumption, without any qualifying knowledge, would not be to assume that the speaker is particularly committed to racial egalitarianism, because most (not all) people aren't so committed, and because most (not all) people who are favor affirmative action. That's how a heuristic works: it is a cognitive shortcut sacrificing optimality for efficiency.
Anti-Semitism works similarly. It certainly isn't true that every critic of Israel is anti-Semitic, or every criticism is. The problem is that, heuristically, if I know little about a speaker, and I start from a presumption that the average person isn't particularly committed to securing equal standing for Jews, and then I hear a criticism of Israel thrown in -- particularly of the kind rarely (not never) voiced by those who do hold said commitment -- it makes sense for me to default to a skeptical stance.
And Rep. McKinney bears this out. Rep. McKinney was one of the more virulent Israel critics when she served in Congress, but she wasn't doing the sort of flagrantly racist and judeophobic stuff we're seeing right now. Nonetheless, the Jewish community, drawing on its long experience in recognizing anti-Semitism (a survival skill we've had quite a few generations to hone) recognizes something quite askance. And given her playing footsie with the worst sorts of bigots and hate-mongering maniacs, I think our intuitions were quite warranted.
So where does this leave the Israel critic who genuinely cares about the liberation of all people, including Jews? Well, the first step of respect is recognizing our vulnerable status and not demanding our trust as an entitlement. Trust is something earned through listening, through respectful dialogue, through a demonstrating willingness to reassess and reevaluate your views, through agreeing to view those you know the least about in their strongest possible light. People who have done the hard work of showing themselves to be allies will find a welcome ear in our community. But persons who openly flaunt their unwillingness to listen, who traffic in arrogant pathologizing and psychoanalyzing -- these persons cannot be surprised when I view their professed commitment to my equality with significant skepticism.