That logic can be used to suppress most other political/religious ideologies and speech. If all it takes to justify censorship is a slippery slope argument that

That logic can be used to suppress most other political/religious ideologies and speech. If all it takes to justify censorship is a slippery slope argument that "when XYZ ideology gains enough real following the resulting implementation attempts probabilistically/historically lead to a suppressed society with hateful class division and mass death" -- then everything from Marxist writing to religious proselytizing qualifies for banning too.