Republicans have made a demographic bet: By artificially inflating the white percentage of the electorate (by throwing up barriers for poor and nonwhite Americans to vote) and driving white Christian turnout sky-high with a combination of cultural resentment and xenophobia, they figure they can extend the lifespan of their increasingly rural, male, non-college-educated base. After a while, however, you run out of white evangelicals. That is precisely what is happening at an unexpectedly speedy pace.


Pew Research finds: “The religious landscape of the United States continues to change at a rapid clip. In Pew Research Center telephone surveys conducted in 2018 and 2019, 65% of American adults describe themselves as Christians when asked about their religion, down 12 percentage points over the past decade.” The ranks of the most progressive segment of the electorate, religiously unaffiliated ("atheist, agnostic or "nothing in particular’ ") have risen to 26 percent, a nine-point bump since 2009.
Among white, non-Hispanic Americans, Christian identification is down 12 points, while the population of religiously unaffiliated is up 10 points. The problem for Christian affiliation gets worse with each generation: “More than eight-in-ten members of the Silent Generation (those born between 1928 and 1945) describe themselves as Christians (84%), as do three-quarters of Baby Boomers (76%). In stark contrast, only half of Millennials (49%) describe themselves as Christians; four-in-ten are religious ‘nones,’ and one-in-ten Millennials identify with non-Christian faiths.”


Considering how reliant they are on white Christians — evangelicals in particular — Republicans are unlikely to survive outside deep-red confines when they lose 12 points in the pool of the most reliable Republican voters. Republicans have created a zero-sum game wherein the increasingly racist and radical appeals to white Christians needed to drive high turnout alienates a substantial segment of the growing nonwhite and/or unaffiliated electorate. They are doubling down on a diminishing pool of voters as they crank up fierce opposition among the fastest-growing segments (millennials, nonwhites) of the electorate. Soon, the math becomes impossible outside of highly gerrymandered congressional districts and rock-ribbed conservative states.
A Pew analysis from March highlighted just how critical this shrinking pool of voters — white evangelicals — is to the survival of the Trumpized Republican Party. About 70 percent of this segment of the electorate supported Trump, with a huge dropoff when one moves from white evangelicals to mainline Protestants (48 percent of this group in Pew’s January 2019 poll supported Trump). It gets worse for the GOP from there: “Religiously unaffiliated Americans consistently express among the lowest levels of approval of Trump’s performance, ranging from 17% to 27% across the polls the Center has conducted since the president assumed office. Most black Protestants and nonwhite Catholics also have disapproved of the way the president handles his job.”
We saw how hyper-reliance on a shrinking portion of the electorate played out in 2018. Red states (which happened to have incumbent Democratic senators on the ballot) such as Indiana, North Dakota and Missouri got redder, while the rest of the country, especially in the suburbs, shifted to the left. That is how Democrats picked up a net gain of roughly 40 House seats and captured more House votes nationwide (53.4 percent vs. 44.8 percent).


When a different set of Senate seats are up for grabs in 2020 — that is, many blue or purple states with GOP incumbents — the Republicans’ bet on white evangelical voters does not look so smart. Hence, Sen. Cory Gardner (R-Colo.), Martha McSally (R-Ariz.) and Susan Collins (R-Maine) go onto the endangered species (Republicans without enough votes from white, rural Christian voters) list.
The electoral college artificially inflates the value of those red, rural states, but you cannot win the presidency based purely on the Deep South and Great Plains. With each election, the Republicans’ situation becomes more precarious. No wonder they are so enamored of voting barriers that artificially depress turnout among nonwhite voters.

Jennifer Rubin writes reported opinion for The Washington Post.