When pundits describe the Americans who sleep in on Sundays, they often conjure left-leaning hipsters. But religious attendance is down among Republicans, too. According to data assembled for me by the Public Religion Research Institute (PRRI), the percentage of white Republicans with no religious affiliation has nearly tripled since 1990. This shift helped Trump win the GOP nomination. During the campaign, commentators had a hard time reconciling Trump's apparent ignorance of Christianity and his history of pro-choice and pro-gay-rights statements with his support from evangelicals. But as Notre Dame's Geoffrey Layman noted, “Trump does best among evangelicals with one key trait: They don't really go to church.” A Pew Research Center poll last March found that Trump trailed Ted Cruz by 15 points among Republicans who attended religious services every week. But he led Cruz by a whopping 27 points among those who did not.