Mencken regularly disparaged representative democracy, populism, creationism and the failure of the middle class to live up to his intellectual standards.
He was once arrested for selling "obscene, lewd or lascivious" material in Boston that had already been banned there (though the offending content was his political magazine The American Mercury, not anything juicily tittilating).
He offended Christians so regularly that he was called "the Anti-Christ of Baltimore," by Christian writers.
Mencken was a columnist at a time of tremendous competition among newspapers, often three, four, five or more in a single city, who understood the attention-getting value of the outrageous opinion. His were just more finely crafted and well expressed than competitors plowing the same ground.
He was glib, literary, well read, intellectual and extraordinary in his contributions to arguments about political and societal issues during the Roaring 20s, the Great Depression, World War II and the early days of the Cold War.
He was also an etymological commentator who wrote a significant analysis of the divergence between American English and British English – a detail about the diversity of the language Arizona's English-only legislature has failed to address or clarify.
He offended people in ways that may not have prompted them to think, but did raise and defend important points of view in public political debate.
In Arizona he'd be fined or on his way to prison after nearly every book or column.