Great-Grandma and Great-Grandpa’s generation, born between 1928 and 1945, is 85 percent Christian (57 percent Protestant, 24 percent Catholic). Their Baby Boom children are 78 percent Christian. The Generation Xers are 70 percent Christian, and Millennials are between 57 and 56 percent Christian depending on when they were born. Americans are dropping out of church, marrying outside the faith they were raised in, and switching confessions at record rates. In 2014, 22.8 percent of American adults described themselves as unaffiliated with any church.

The loss of congregants has been most marked among mainline Protestants and Catholics, but evangelical churches have declined too (at a slower pace).

What does this mean for politics? It’s good news for the Democrats. Religious observance, like marriage, is a good predictor of political preference. Adults with no religion lean Democrat by 36 points. Young, white evangelical Protestants lean strongly Republican. The more religious identification sags, the fewer young Republicans there are.

Similarly, married adults tend to vote Republican, while singles, especially single women, lean heavily Democratic. Fifty-three percent of married women voted for Mitt Romney in 2012 (there is also overlap between religious identification and the tendency to wed). But marriage is declining. Whereas 65 percent of American adults were married in 1980, just 51 percent of adults were married in 2012. Among the 20-to-34-year-old cohort, 57 percent are never-marrieds.