Also, if you're a critic of the policies of the state of Israel, you're an anti-semite, but we have no idea from whence this new wave of anti-semitism comes.
I've not seen much of that sentiment, actually. A common opinion is that holding Israel to a double standard while not demanding the same from other countries (particularly the Arabs) is anti-Semitism. I think this idea has merit, but it gets murky, and can be used to try to whitewash Israel's actions. But merely criticizing Israeli policies is not anti-Semitism. If it were, then the entire Israeli left are anti-Semites.
Thanks for the explanation re: leftism and liberalism. I think I probably agree.
As for this above bit, I totally disagree. That's basically the only tactic of the entire (powerful) "Jewish Lobby"*; if you disagree with us, you're an anti-semite. Doesn't work in Israel, of course, because accusing Jews of anti-semitism is lunacy in a country full of them, but it works well in the West. Who wants to be called a Nazi? So you censor your even-handed documentary on Ariel Sharon or you vote to send over some more illegal cluster munitions, but you forget about it because if you had believed you had been forced by a powerful Israeli-funded lobby to send illegal cluster munitions to Israel, you'd be an anti-semite, wouldn't you?
As for the double-standard thing: I've yet to see it. AIJAC et al often accuse Israeli critics of anti-semitism on the grounds that it is unfair to criticise Israel at all, since it is not The Worst Country In The World. Ignoring the obvious point that they criticise a bunch of countries- not all of them can be The Worst Country In The World after all- this is an invalid ad hominem attack anyway. You don't have to be The Worst Country to do something wrong. Is it right to blockade Gaza or wrong? This should be argued on the merits. Just because AIPAC says everyone who disagrees must be an anti-semite does not make it right.
Now, why is Israel in particular a big issue in the left? Who cares? Are they right or wrong? That's all that matters. I think they're mostly right.
* I think a better term is Likud Lobby, firstly because they don't represent most Jews, secondly because they don't represent the interests of Israel and thirdly because they do insist everyone march in lock-step with Netanyahu et al, or you're an anti-semite. Even if you're Jewish, you're an anti-semite if you disagree with Netanyahu, AIPAC or the AIJAC.