Jeremiah Wright is one example - passionately leftist, but believes that Jewish control of American foreign policy (particularly in Israel/Palestine and Iraq, driven by neoconservative/Jewish ideology) has led America astray. He's just the latest of a long list of similar-sounding people. A lot of the anti-'fat cat banker' sentiment veers into anti-Jewish tropes at times, too. The comment pages of the Guardian's articles on the Middle East are full of this kind of rhetoric - so is Indymedia, both of which are ardently leftist publications. This is generally where the loony left and the loony right start to look more and more alike - oh, they advocate entirely different policies, but they both like to blame the Jews, albeit from opposite ends of the spectrum.

edit: Oh! I forgot all about the New World Order conspiracy bullshit and the anti-globalization thing. Liberal (and libertarian) chic, but full of portentous conspiracy theories about some secret cabal trying to take over the world... kinda an updated Protocols of the Elders of Zion.