Systematic delegitimization of Zionism has been "Politically Correct" since the infamous UN "Zionism is Racism" resolution of 1975<, and it has not abated. This situation is mirrored on the World Wide Web. Depending on the day, five or six of the ten first links retrieved by a Google search for "Zionism" are anti-Zionist polemics, including some obnoxious racist diatribes. "True Torah Jews Against Zionism," the top-ranked Web site, represents a tiny minority of  medieval Jewish religious fanatics who insist that only their view is correct and brands every other view as heresy. Another site offers us the following enticing introduction: "What Zionism is -- and its pernicious influence upon the USA." Sounds  like that could have been plagiarized from Mein Kampf, with "Zionism" replacing a certain other word. Here is another: "A Crude Attempt To Equate Anti-Zionism With Anti-Semitism ... Jewish Persecution - A Primary Tool Of International Zionism"  "International Zionism" used to be the International Jew-Bolshevik conspiracy in the good old Third Reich of course. Many of the Web sites that insist they are not racists and that criticism of Zionism is not racist have links to Mein Kampf, Protocols of the Elders of Zion and similar racist materials.  

Anti-Zionism sometimes masquerades as "peace" or "peace and justice" advocacy. Destroying the national home of another people cannot have anything to do with either peace or justice.

Why they succeed - Anti-Zionist and Islamist Web sites link to each other and support each, passing around the same materials and publicizing each other's efforts.