To locate Joe Biden’s electoral problem, you need only to look on Sunday morning. Polling shows the mass-attending Catholic president trails Donald Trump by 10 points among those who attend religious services a few times a year or more. The score is reversed with voters who report they seldom or never attend church, with Biden leading by 10.

It’s the starkest divide in the electorate – and one that political journalists rarely mention, perhaps because, as a profession, journalists are more removed from religion than the average American.

Trump’s advantage with white evangelical Protestants is widely understood, but he also leads Biden by healthy margins among less politically conservative Christians. These findings in the recent Marquette Law School’s national poll of registered voters showed Biden trailing Trump by 18 percentage points with other members of his own Catholic faith, and behind Trump by 16 among adherents of mainline protestant denominations, which would include groups like Methodists, Presbyterians, and Episcopalians.

Those numbers are in the same range as the 24-point lead Trump posts among self-described “born-again” evangelicals. The same poll shows the race is reversed with non-Christian voters, with whom Biden holds a commanding 33-point advantage.