Joe and Betsy Stone, part of the estimated 23 percent of religiously unaffiliated Americans, together at their home in Springfield, Va. (Bill O'Leary/The Washington Post)

Joe Stone is part of an enormous but invisible voting constituency.

A “troubled atheist,” the retired Virginia accountant calls himself spiritual, celebrates Christmas and defines religious as the need to “do good.” He says organized religion — Christianity as well as Islam — has “gone off the deep end” and political candidates who emphasize the rightness of a certain faith turn him off. At the same time, Stone calls himself “religiously open-minded.”

When Democratic presidential candidate Bernie Sanders told a New Hampshire town hall last month that religion is a way of saying all people are connected, Stone agreed. “He is speaking directly to me,” he said.

Stone is part of a massive group of Americans who reject any label or affiliation to describe their faith. At 23 percent of the U.S. population, this left-leaning group called “Nones” are the Democratic parallel to the GOP’s white evangelicals — except without organization, PACs, leadership and a clear agenda. They do, however, have one big expectation of political candidates: Be ethical, and go light on the God talk.

The Nones’ impact will be tested on Super Tuesday, when multiple states with large unaffiliated populations hold contests: Virginia, Massachusetts, Minnesota, Vermont and Colorado. So far, Sanders has a large edge among Nones.

A huge group that skews under 40, white and non-immigrant, the Nones want politicians to tone it down not because they’ve made some final determination about God — the vast majority are believers — but because they are fed up with religious institutions they see as corrupt and discriminatory. And in the process, they are rewriting the country’s political discourse on morality.

Experts say the country is just beginning to feel Nones’ political power, in good part because their turnout has been low at about 12 percent — unsurprising for a disproportionately young group. But that is likely to change, with early research suggesting they are not inclined to become more religious as they grow older.

Political scientist David Campbell, who focuses on religion, compared the Nones of today to evangelicals of the 1970s — who grew in number and slowly became a massive, organized political force.

The Fix's Aaron Blake sets up the stakes for Republican and Democratic presidential candidates on Super Tuesday. (Peter Stevenson/The Washington Post)

“You might say we are awaiting the emergence of a secular Jerry Falwell,” said Campbell, who chairs the political science department at the University of Notre Dame.

With their socially liberal viewpoints, Nones will pull the Democrats to the left — which is already happening with Sanders, said Mark Rozell, dean of the government and policy school at George Mason University and author of multiple books on religion and politics.

“It will make a profound change in American politics in the long run. Put up a candidate who challenges people’s right to love who they want and make decisions about their own lifestyles, and see what happens among the unaffiliated. A lot of other issues go to the back burner,” Rozell said.

If Sanders or Democratic rival Hillary Clinton start talking too much about religion as the race veers South, among Nones that would be “dangerous,” he said.

‘We need a revolution’

Nones talk about tolerance, fairness, choice and “making the world a better place.” In interviews some describe their worldview as being more authentically holy than people who cite Scripture and denominational labels.

“My girlfriend said, ‘Greta, you’re the best Christian I know that doesn’t go to church,’ ” said Greta Clark, 81, of Youngstown, Ohio, an agnostic who says her religion is “do no wrong.” Stone says he has an answer for Christians who are skeptical of Sanders’s bio: “Wait a minute, Jesus was a Jewish socialist.”

In addition to their skepticism about religious institutions, Nones share anger at secular institutions they feel are immoral, interviews show. Their political priorities include reducing big money’s influence on politics, raising wages and making college affordable. They do not trust government to police personal morality.

“We need a revolution at this point because corruption is so vast,” said Cheryl, a 43-year-old chief financial officer from Atlanta. She spoke on condition that her last name not be used because she said the stigma of being not religious in the South would harm her career and her child. She doesn’t like it when candidates talk about religion, but it bothers her less if it seems like lip service — evidence that they probably won’t apply dogma to public policy. If they’re saying it just to get elected, that’s more okay, she said.

“It doesn’t bother me because I’ve done the same thing, tried to pass,” she said. “I have no idea whether there is a God and I don’t think that’s an answerable question.” Before she got married, however, she put “atheist” in her dating profile instead of “agnostic” only to turn off fundamentalist Christians who might misinterpret her as open to their belief.

Although most evangelicals and Catholics say terrorism is their top voting priority, Nones say theirs is the economy, according to a Washington Post-ABC News poll in December.

The major check on Nones’ political power is their lack of group awareness.

“This cohort is as large as evangelicals, but very poorly organized, and they don’t have the discipline or political reflex. But you can’t tell me campaigns aren’t thinking about them, especially the Democrats,” said Jacques Berlinerblau, a Georgetown University sociologist who has written several books about the role of religion in politics. Democrats, he said, have to straddle the Nones, most of whom feel candidates are talking too much about their faith and prayer, and the rest of the Democratic faith coalition — which includes progressive Jews, Catholics and Protestants — “who don’t mind it as long as it doesn’t get overwrought.”

A quarter of President Obama’s voters in 2012 were religiously unaffiliated — by far the largest “faith” group in his coalition. Perhaps in consideration of his religiously independent supporters, the president gave the first inaugural nod in his 2008 address to “nonbelievers.”

At the moment Nones are breaking hard for Sanders, a secular Jew who seems ambivalent about how to portray his faith. He has said he is not religious and chose to spend last Rosh Hashanah — a major Jewish holiday — speaking to evangelicals at Liberty University. When he won in New Hampshire last month, becoming the first American Jew to win a presidential primary, Sanders didn’t mention that fact in his victory speech, instead calling himself the “son of a Polish immigrant.” However, last fall when The Washington Post ran an article entitled: “Bernie Sanders: Our first non-religious president?” the Sanders campaign quickly emailed the reporter to point out a September interview about Pope Francis in which the senator referred to a “belief in God . . . that requires me to do all that I can to follow the Golden Rule.”

‘A delicate balance’

Mike McCurry, a communications consultant to candidates and faith groups who served as press secretary to Bill Clinton, said top Democratic advisers to campaigns “just don’t get” the role of faith groups — including the Nones.

“They don’t see it as a political constituency to mobilize,” McCurry said. That said, “it’s a delicate balance. [Nones] want to hear about your values and what gives you a moral stake, but they don’t want an agenda that’s forced down their throat.”

In fact, the Nones are a complex and sometimes contradictory group. They believe in God — but on their own terms. They don’t particularly want to hear about religion, but they aren’t anti-religion.

Clark said she doesn’t believe in confession, doesn’t think she believes in God, considers herself a Christian “in some ways,” thinks candidates shouldn’t mention religion and is disgusted by “houses of worship fancied up with icons and statues, big churches built from poor people’s money.” But she and her husband sent their now-grown sons to Catholic school. To her, the main election issues are things like roads, bridges and clean water. The issue of water contamination “is a disgrace.”

Of Sanders’s statement that religion means “we’re all in this together,” Clark said: “I’ve got to agree with him there. But he has the young people all worked up, they think they’re going to get something for nothing. It don’t work that way.” Of anyone, she said she prefers Sanders, but she is undecided.

Stone sees in Sanders a glimpse of his youth — a time when religion seemed less angry, less divided, when his folks could buy a home in Massachusetts for $8,000, when the system didn’t seem rigged. More recently, he and his wife, Betsy, — both accountants — “retired reluctantly, more or less.” Not that he’s complaining or bitter, and he has lots of positive things to say about religious relatives and pastors he’s known. Stone even regrets a bit not raising his children to be more religious, if only so that when religion and Scripture come up in conversation, they’d be able to more knowledgeably talk — or debate.

Joe and Betsy Stone, part of the estimated 23 percent of religiously unaffiliated Americans, are seen in their home in Springfield, Va. (Bill O'Leary/The Washington Post)

Stone sees Sanders as serious about getting money out of politics. He said he trusts Sanders when the senator talks about his spirituality. He even trusts Clinton — a Methodist his age — when he heard her tell an Iowa voter: “I am a person of faith, I am a Christian, I am a Methodist.” But he wishes there was no need for candidates to state their religion.

“I wish we didn’t have to talk about religion in politics. This is not a religious race,” Stone said. He grew up in a big religious family but feels church has become arrogant and intolerant. “We should be a spiritual country, meaning we should endeavor to have a good government in the eyes of whatever God you feel is right, or in the eyes of no God.”

Christianity has become too broken into sects and intolerant, “it’s split up more,” he said.

“Back then Muslims were peaceful happy people and, for whatever reason, they got angry. Religions have gotten wacky,” Stone said. “Morality comes from another place. It’s a chicken or egg thing. The morality came before the stories” of religion.

‘A bunch of little things’

Alexis Echevarria, 20, calls herself a None because “I don’t want to label myself. I believe in a bunch of little things, other religions,” including the Catholicism to which her family holds fast and in which she was raised. But in recent years she has started questioning some church teachings, doesn’t like labels and sees her peer group in Katy, Tex., outside Houston, as split on religion — half her friends are religious and half are not. She values choice, whether that comes to whether to go to church, accept abortion or homosexuality or to even call yourself a believer.

“I’m open to everything and everyone,” Echevarria said, including candidates who talk, or don’t talk, about their faith. She has heard “very very little” about candidates’ religion, except Republican presidential candidate Donald Trump talking about religion and immigration, “which is baloney,” she said.

In truth, she said, she has been paying limited attention to the campaign, except that she knows she likes Sanders for her first-ever presidential vote. The senator’s talk about raising the minimum wage and making college more affordable “would be awesome.”

Her feelings about Sanders reminds her of the ones she had about Mitt Romney, the 2012 Republican presidential nominee. “Sanders seems like a genuine guy, and so did Romney,” she said.

Asked how she can tell if a candidate is speaking genuinely about their faith, Echevarria’s sunny, non-judgmental vocabulary shifted. “I was told candidates lie,” she said. “I’m guarded with everyone. Open, but guarded.”

Reseacher Scott Clement contributed to this report.