Looking for a new villain to account for the polarization and sheer meanness of our current politics? Instead of blaming deep divisions over race, misogyny, immigration, income inequality and the bellicose Twitter reign of President Trump, many have seized on secularism as a scapegoat for everything that keeps politically conscious and conscientious Americans awake at night.

The theory is that America’s post-2000 decline in churchgoing, especially among the young, has bred unhealthy political obsessions that offer rituals and a sense of community formerly provided by religion. The idea that “politics has become a religion,” as the columnist Michael Gerson put it in The Washington Post, is used tortuously to attack both Trumpism and progressivism.

American politics was once kinder, Andrew Sullivan argued in New York magazine, because “if your ultimate meaning is derived from religion, you have less need of deriving it from politics or ideology or trusting entirely in a single, secular leader.” He continued, “Now look at our politics. We have the cult of Trump on the right, a demigod who, among his worshipers, can do no wrong. And we have the cult of social justice on the left, a religion whose followers show the same zeal as any born-again evangelical . They are filling the void that Christianity once owned.”

But the concept of secularism as a breeding ground for aggrieved politics is a delusion, rooted in contempt for the beliefs of nonreligious Americans and ignorance of or indifference to the role of secularism throughout American history. It is also based on ahistorical nostalgia for a nation in which religion — particularly Christianity — was a totally beneficent influence.