I'm reminded of the "Come out - we have you surrounded" meme where the mentally insane man is hiding behind a desk with a shotgun screaming "Get out of my head" or "I hate the Antichrist", because that's how thinking about these groups make me feel
The Holocaust and Hitler basically define modern Western morality, and Zionism's claims to legitimacy are closely related to those concepts. Associating someone with "Hitler" or "antisemitic" is worse than calling them "bin Laden" or "slavemaster".
Other popular foreign lobbies in Washington, from Ukrainian, Taiwanese, Kurds, Uyghurs, don't have nearly the same influence.
There is no better-coordinated or -funded lobbying group than the military-industrial complex, which is, of course, all in on Israel.