Very few Americans today are interested in setting up a community based on 17th-century Protestant notions of biblical morality. But Milton’s pamphlet remains relevant. All societies have certain organizing principles. Freedom of speech is not a first-order good; it exists only to facilitate the flourishing of the society along the lines established by those principles. In America today one of those principles is that discrimination based on race is immoral; people who disagree with this have only one goal — creating a society in which it is not one of those principles. If we do not want to allow this to happen, we should not permit anyone to argue in favor of it.
To pretend otherwise and posture on behalf of the abstract rights of racist crank is not, as “absolutists” pretend, to defend speech but to demean it, to diminish it to the level of undifferentiated random noise. This is because every act of expression takes place against the invisible backdrop of all the expressions not taking place; an argument in the pages of The Washington Post about a murder assumes that murder is a crime, and it would not occur to the reporter that, when seeking comment from the police department and the suspect’s attorney, he should also solicit the opinions of a hypothetical man in Arkansas who thinks that murder should not be a crime. To fail to see how any given act of speech only makes sense in the absence of other possible but absolutely inadmissible expressions is childish. Assuming that a new scholarly biography of Hitler and Holocaust-denying memes traded by basement dwellers on the internet are both “speech,” expressions of potentially equal value whose worth is ultimate determined by what readers decide to make of them, is not an exercise in tolerance; it is nihilism.