OK, I GET IT NOW

I've wondered where the notion that secular humanism is a religion started and Rick Perlstein has one answer:

Here's some background those befuddled Democrats need to know: One of the most robust and effective conspiracy theories on the right, the notion that "secularism" – or, just as often, "Secular Humanism" – is a religion is meant to be taken entirely literally: right wingers genuinely believe it refers to an actually existing religious practice. How do conservatives know? Because, they say, the Supreme Court said so. It was, as religious historian and Lutheran minister Martin E. Marty has written, "an instance where one can date precisely the birth of a religion: June 19, 1961." That was the day the Court ruled in the case of Torcaso v. Watkins striking down the Maryland Constitution's requirement of "a declaration of belief in the existence of God" to hold "any office of profit or trust in this state" — specifically, in atheist Roy Torcaso's case, the office of notary public. In his decision, Justice Hugo Black, writing for a unanimous court, further asserted that states and the federal government could not favor religions "based on a belief in the existence of God as against those religions founded on different beliefs" – and, in a fateful, ill-considered, and entirely offhand footnote explained: "Among religions in this country which do not teach what would be generally be considered a belief in the existence of God are Buddhism, Taoism, Ethical Culture, Secular Humanism and others."

I was also surprised that Maryland had that religious requirement and enforced it.