Those white evangelicals who wield so much political power in America are actually a rapidly shrinking percentage of the population. Photo: Michael S. Williamson/The Washington Post/Getty Images

It’s relatively well-known that the portion of the U.S. population with no religious affiliation has been steadily increasing recently. And for those paying attention to research, it’s also been obvious for a while that conservative evangelicals were beginning to lose “market share” after years of mocking their mainline Protestant cousins of “dying” because of insufficiently rigorous theology and moral strictures.

But now comes a new set of data from years of polling by ABC News and the Washington Post that puts these trends together in a way that might bust some old preconceptions. Between 2003 and 2017, the percentage of adult Americans professing “no religion” grew from 12 percent to 21 percent. And at the same time, the portion of the population made up by white evangelicals dropped from 21 percent to 13 percent. Indeed, the white evangelical population dropped even faster than the white non-evangelical population (which shrank from 17 percent to 11 percent), and the two groups are converging in size.

Among younger Americans, the trends are even starker. In 2003, only 19 percent of adults under 30 professed “no religion.” That percent rose to 35 percent in 2017. That’s compared to only 22 percent who identify with any sort of Protestantism.

When you consider the political power of the different types of believer and unbelievers, these numbers are hard to credit. Recently four members of the U.S. House of Representatives formed a “Freethought Caucus,” dedicated, among other things, to defense of “atheists, agnostics, humanists, seekers, religious and nonreligious persons” against discrimination. Yet those white conservative evangelicals who are now significantly outnumbered by the “nonreligious” have one of the two major political parties catering to them relentlessly; they are also uniformly thought to represent the political “base” for the president of the United States.

If the irreligious ever get serious about flexing their muscles politically, a lot could change in this country, particularly on church-state separation issues. In the meantime, white evangelicals need to get a more realistic sense of their own trajectory, and stop lording it over other people of faith who share their less-than-robust membership trends.