"[A]ny and all criticism of Israel not only can be but must be antisemitic. It is either subjectively antisemitic, in that it consciously and intentionally furthers the goals of the campaign; or it is objectively antisemitic, in that it unconsciously and unintentionally does the same thing. The distinction, if there ever was one, between the two, is now meaningless. Either way, the result is the same: Those who seek to slaughter the Jews en masse are brought a step closer to their goal," - Benjamin Kerstein, Pajamas Media.
The most fanatical elements of a movement seek to Force everyone to choose sides, since they think that that will make their side victorious. Thus Jews who dare to criticize any act of Israel's government or it's citizens, no matter how heinous, are singled out for the most vicious abuse as self-hating Jews. Other critics are anti-semites, effectively indistinguishable from the Nazis.
I don't think this kind of name calling works in the long run. Eventually intelligent people get tired of indulging the shrillest nutjobs and start thinking about their own interests. You ultimately must choose to be a partner of the crazed fanatics or to resist them. So far most American politicians are either disingenuous, gullible, or intimidated enough to bow before the worst excesses of Netanyahu and his settlers. I don't know how long that will work.