That's an argument for active participation in the political process and an engaged electorate, not censorship. To default to the support of censorship of what you disagree with is simply laziness (and antithetical to the fundamental principals of a democratic society). If your government and society can't withstand the free expression and discussion of unpleasant ideas, you have problems with the current implementation of government and society (and the unpleasantness isn't at fault). Masking the symptom doesn't solve the root cause.

To your example, you put misplaced blame on a propaganda machine, not uneducated, unengaged, emotional citizen voters.