“Back in 2016, Trump ran away with the Republican nomination despite a crowded field of candidates, many of whom had real religious bona fides. Texas Sen. Ted Cruz (R-Texas), a member of a Southern Baptist Church in Houston, often quoted scripture during his stump speech. Marco Rubio (R-Fla.) tweeted a Bible verse a day. Yet, despite lack of any religious credibility, Trump won half of the votes of Republicans who attended religious services weekly in 2016, while Cruz only got only 30 percent of their votes and Rubio earned 11 percent.
That was significant, but it would have meant little had he not earned huge support from Republicans who weren’t religious. During the nomination process, two in five Republicans described their religious attendance as “seldom” or “never” according to data from the VOTER Survey, a longitudinal study sponsored by the Democracy Fund that repeatedly interviews thousands of Americans. Among those who said that they never attended religious services, two-thirds were Trump voters in the 2016 Republican primary. Cruz, by contrast, managed just 16 percent of this group. Among those who described their attendance as “seldom,” Trump secured 57 percent of the vote while Cruz only tallied 22 percent.”
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“In 2016, 39 percent of all Republican voters attended church less than once a year. In comparison, just 36 percent said that they attended religious services at least once a week.”
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“In 2008, 44 percent of Republicans reported that they were in church at least once per week. By 2022, that number had slipped to just 35 percent. In comparison, the share of Democrats who attended weekly only declined five percentage points (23 percent to 18 percent) during the same time period.”
https://www.politico.com/news/magazine/2023/09/12/republicans-church-trump-00113565