(RNS) — In recent weeks there’s been some anxiety in Democratic quarters about surveys indicating that Latinos may be less likely to vote for Joe Biden in November than they were for Hillary Clinton four years ago. Latino Catholics have long been a strong Democratic constituency, and any sign of disaffection on their part could pose real trouble in states such as Florida, Arizona and Nevada.

Now comes the latest Washington Post/ABC News poll, and it suggests that the big news with the Catholic vote this year may actually have to do with a shift in white Catholics’ votes toward Biden. According to the poll, white Catholics now prefer him to President Trump by 51% to 45%. That’s a sea change from 2016, when they chose Trump over Hillary Clinton 61% to 37%.

As the Post/ABC release notes, “Only two previous Democrats have done as well with white Catholics in the last 44 years, both winners — Jimmy Carter in 1976 and Clinton in 1996.” If such a 30-point turnaround does indeed take place, Biden will be our next president.

The significance of the shift is best gauged in regional rather than national terms. According to the most recent accounting from PRRI, white Catholics now constitute just 61% of the U.S. Catholic population. Given that Catholics were 23% of the vote in 2016, that puts the white Catholic vote at 14% of the total. A 30-point shift would thus move the overall popular vote total 4.2 percentage points toward Biden.

RELATED: Barrett hearings will play into Trump’s hopes to claim Catholic high ground

This combination image of two photos shows President Donald Trump, left, and former Vice President Joe Biden during the first presidential debate Tuesday, Sept. 29, 2020, at Case Western University and Cleveland Clinic, in Cleveland, Ohio. (AP Photo/Patrick Semansky)

But the truly big impact would be in Pennsylvania, Ohio, Michigan and Wisconsin, swing states carried by Trump in 2016 where 80% to 90% of the Catholics are white. The 2016 exit polls indicate that Catholics in those states made up about the same percentage of the vote and voted for Trump at about the same rate as white Catholics nationally.

And in those states, the difference between the 2016 Trump-Clinton vote and 538′s current Trump-Biden polling averages is between eight and nine percentage points. In each case, three-quarters of that shift can be attributed to the white Catholic shift found by the Post/ABC poll.

To what should we attribute the shift?

White Catholics have never been as enthusiastic about Trump as white evangelicals (whose support the poll finds to be nearly unwavering). Although Biden is at odds with his church’s teaching on abortion, so are more than half of white Catholics. And across the spectrum of other Catholic social teachings — concern for the poor, immigration, the death penalty, healthcare — white Catholics have much more reason to prefer Joe Biden.

Maybe most importantly he’s one of them, recognizable in parishes across the Northeast and Midwest as the classic Mass-going pol-from-the-‘hood who knows your name and feels your pain.

Yes, as they’ve grown richer and more suburbanized in recent decades, white Catholics have trended Republican. But the atavism of the old urban ethnic faith, it seems, can still be resurrected.