Secularization is transforming the left, too. In 1990, according to PRRI, slightly more than half of white liberals seldom or never attended religious services. Today the proportion is 73 percent. And if conservative nonattenders fueled Trump’s revolt inside the GOP, liberal nonattenders fueled Bernie Sanders’s insurgency against Hillary Clinton: While white Democrats who went to religious services at least once a week backed Clinton by 26 points, according to an April 2016 PRRI survey, white Democrats who rarely attended services backed Sanders by 13 points.

Sanders, like Trump, appealed to secular voters because he reflected their discontent. White Democrats who are disconnected from organized religion are substantially more likely than other white Democrats to call the American dream a myth. Secularism may not be the cause of this dissatisfaction, of course: It’s possible that losing faith in America’s political and economic system leads one to lose faith in organized religion. But either way, in 2016, the least religiously affiliated white Democrats—like the least religiously affiliated white Republicans—were the ones most likely to back candidates promising revolutionary change.

The decline of traditional religious authority is contributing to a more revolutionary mood within black politics as well. Although African Americans remain more likely than whites to attend church, religious disengagement is growing in the black community. African Americans under the age of 30 are three times as likely to eschew a religious affiliation as African Americans over 50. This shift is crucial to understanding Black Lives Matter, a Millennial-led protest movement whose activists often take a jaundiced view of established African American religious leaders. Brittney Cooper, who teaches women’s and gender studies as well as Africana studies at Rutgers, writes that the black Church “has been abandoned as the leadership model for this generation.” As Jamal Bryant, a minister at an AME church in Baltimore, told The Atlantic’s Emma Green, “The difference between the Black Lives Matter movement and the civil-rights movement is that the civil-rights movement, by and large, was first out of the Church.”