Do you know how to floss?” Sister Mary Ellen asks me, deadpan. “Because we do.”

The “we” she’s referring to is a group of 10 Catholic nuns traveling the country by bus to spread the gospel of tax reform. And the flossing she’s talking about isn’t dental hygiene; it’s a deceptively difficult dance move.

“We just read a tutorial last night and practiced in our chairs, but if you know how to do it for real, we’re looking for some teachers,” Sister Mary Ellen notes.

Sister Susan, I’m told, has perfected the dance, and she’s hoping to show me. But we’re in a moving bus. The other sisters warn her, laughing. “Don’t break a hip!” “Don’t fall down!”

Susan McCarthy, a steadfast Sister of the Divine Compassion, is undeterred. The 73-year-old stands up in front of me to demonstrate, shaking her hips from side to side while her arms wave in an opposite motion. “Something like that?” she grins at me.

We’re in a slick tour bus heading down Interstate 87 towards the sisters’ next stop in Morristown, and we’re pulling out of Kingston, where they held a rally outside the offices of Republican Congressman John J. Faso. The bus is basically a giant, rolling billboard. Across the side it bears the words “Tax Justice Truth Tour.” On the back, a message from Pope Francis: “A good Catholic meddles in politics.”

The “Nuns on the Bus” tour was created by Sister Simone Campbell, a lawyer, lobbyist, and Sister of Social Service. Campbell is the executive director of NETWORK Lobby for Catholic Social Justice, a lobby group founded in 1971 by a group of Catholic nuns in response to the Vatican II reforms. It’s her sixth time out in the tour bus; the first tour, in the summer of 2012, was launched to challenge Paul Ryan’s budget proposal.

This year, the trip is a rebuke of the Republican tax bill of 2017. The nuns advocate for “reasonable revenue for responsible programs,” which means taxing top earners at a higher rate and spending the money on safety-net programs, accessible health care, and public infrastructure rather than the military. The money is there, the nuns believe; we’re just spending it in the wrong place.

“I’m a sore loser,” says Sister Simone. “So I want to say, we don’t have to keep this.” Her message of economic equality is twofold: the rich shouldn’t get disproportionately large tax breaks, more taxes should be spent on social programs that benefit low and middle-income Americans.

“We are the body of Christ, and if the body is hurting, we can’t stay silent,” says Sister Simone. “I mean, we’ve got to act. And so for me, it’s that mandate to be a healing presence, to stir people up, to care, to engage.”

Sister Simone, a Sister of Social Service, is both warm and sarcastic, exuding what she likes to call “sassy sister spirit.” Her lobbying work in Washington may defy the stereotypes of her professions, but she is also a deeply spiritual woman who strives to embody her faith.

That means loving everybody—even President Trump. “That’s very hard,” she says. “But that’s what we’re called to. Jesus said love your enemies, and what a ridiculous idea that was. It’s a big challenge.”

At a retreat a few years ago, she boasts, “I got to a holy place where I even loved Mitch McConnell.”

Underpinning Sister Simone’s work is her belief that individual works of charity can’t solve structural problems. Catholicism has long put an emphasis on good works, and nuns are often the one to carry out the church’s mission of charity. But even if every church opened a soup kitchen, hunger wouldn’t go away, the nuns on the bus argue. And who better than nuns to spread this message? They have seen firsthand what the problems are and how they need to be fixed.

Catholic social justice is about far more than the Ten Commandments, explains Sister Mary Ellen Lacy, a Daughter of Charity who also works at NETWORK. “It’s the Sermon on the Mount, ‘Blessed are the poor in spirit,’” says Sister Mary Ellen. “It’s not the do-nots, do-nots, do-nots. Jesus came and he told us what to do and how to treat each other.”

“I believe the role of the federal government is to do for the community what the community can’t do for itself,” says Sister Simone. In the half a day I spend on the bus, she repeats the following phrase at least three times: “We must end the unpatriotic lie that we’re based in individualism.”

The nuns’ bus tour began in Santa Monica, California, on October 8 and will end on November 2 with a “Fiesta for the Common Good” in Mar-a-Lago, Florida. Along the way, the nuns are stopping in 21 states, hitting critical areas adversely affected by GOP policy. By the time they arrive, they’ll have traveled nearly 6,000 miles.

Every morning, the sisters pray together for a half hour before they board the bus, which is too distracting for quiet reflection. It’s not just the noise; the bus is filled with snacks. The nuns receive baked goods and other gifts from visitors along their bus route, and when I join them, their kitchen is piled high with brownies, cupcakes, donuts, bags of apples and oranges. The sisters share a U-shaped banquette in the back, and half a dozen staff members ride up front.

At each stop, the sisters ask visitors to sign pledge cards, and then sign the bus. “So by the time we get to Mar-A-Lago, everyone is on the bus,” says Sister Simone. On the road, they’re active on Twitter and write daily blogs about the trip.

Sister Simone estimates their reception has been “93 percent really really positive.” She says she even managed to make nice with a group of Catholic anti-abortion activists who met them in protest outside of Representative Claudia Tenney’s office in New Hartford, New York.

The tour consists of three main types of events: lobby visits to district offices, rallies, and town-hall meetings. The sisters tell me they’ve heard from people across their tour who couldn’t get their elected representatives to listen to their concerns until the nuns came to town. Most representatives don’t keep their policy staff in district offices, though, which means the nuns often find themselves talking in circles around the low-level staffers, who seem overwhelmed by the meetings.

At town-hall meetings, their signature event, the sisters try to show the impact of the tax bill using avatars of the five income quintiles of the American populace. Each character is acted out by a sister who takes steps forward or backward in the auditorium based on how the quintiles are impacted by the 2017 tax bill and proposed GOP budget cuts to public programs. The characters are all based on real people the sisters have met on past bus tours. “It’s not composite,” explains Sister Mary Ellen.

There’s Eddie, a 36-year-old father who earns $24,000 per year and relies heavily on social services; Nikki, a 33-year-old teacher’s aide and server who makes only $42,000 to support a family of six; Diana, a 30-year-old mother and school teacher who makes $66,440 and is saddled with school debt; Adelaide, an 87-year-old widow who receives $97,500 per year but doesn’t know how she’ll afford a nursing home; and Jonathan, a CEO who makes $245,000 per year.

In addition to members of the five quintiles, there’s George, a hedge-fund manager and member of the 1 percent making $1,453,000 per year mostly from investment returns.

By the end of the exercise, Eddie and Nikki have taken steps backward, while George is sent walking to the far end of the room. “You see it’s not just what you get, it’s what you lose,” says Sister Simone.

In Buffalo, Sister Erica Jordan met an older woman who has worked her entire life and is worried about becoming homeless as a result of the proposed GOP budget cuts. “I’m in Eddie’s quintile,” she told Sister Erica.

In Beaver, Pennsylvania, the nuns spoke with the mother of a 9-year-old child who can’t hear or speak who told them she hopes she and her husband don’t die before their daughter because they don’t know who will take care of her.

In Akron, Ohio, the sisters met a man who had just put his 68-year-old wife into an Alzheimer’s unit but doesn’t know how to pay for it.

The nuns on the bus have heard a clear message: Americans are worried about what is coming next and they don’t know who will listen to them. “When these politicians talk so cavalierly about taking away the Affordable Care Act; they have no idea what terror it puts into the heart of our people,” says Sister Simone.

Nuns are not part of the clerical structure and are considered lay people within the Catholic church, meaning they the lack the institutional power that priests have.

This frustrates many of the sisters. As in many institutions, women in the church often do the work behind the scenes but don’t get recognition for it. “Father gets up and his name is on the letterhead, but sister is making the committees work, sister is getting people to show up, sister is doing community organizing behind the scenes,” explains Sister Betsy Van Deusen, a Sister of St. Joseph.

Still, their lack of power has an upside: Many of the sisters feel they have nothing to lose by speaking openly about politics, and, perhaps more importantly, the public recognizes them as a group apart.

In 2012, the Vatican investigated the Leadership Conference of Women Religious, the largest group of Catholic nuns in the United States, for being focused too much on social justice and not enough on culture-war issues of abortion and homosexuality. The Vatican criticized the sisters for espousing “certain radical feminist themes incompatible with the Catholic faith.” But the public rallied behind the nuns, and Sister Simone organized the first “Nuns on the Bus” tour just months later.

She looks back on the Vatican inquiry as a turning point. “We always said, what if Rome gets upset?” she says. “Rome got upset, and we didn’t die. In fact, we flourished.” What’s more, in the wake of the sex scandals roiling the Catholic church, the sisters believe they offer the promise of trust and credibility.

As part of their vow of poverty, the sisters renounce individual ownership. “Their interest is purely philosophical, religious, what’s best for the world and the country,” says Toni Robinson, a Quaker and tax-law professor who drove more than two hours to see the nuns speak in Kingston.

Her colleague, Mary Ferrari, was raised Catholic but no longer attends church regularly. “I think that the sisters, the nuns, are representative of what the Catholic Church should stand for in this country,” Ferrari says.

Nuns are also funny, which is disarming, according to Sister Simone. “I think it makes people laugh,” she says. And they do make people laugh, not just when they’re flossing.

As our bus ride comes to an end, the nuns are greeted by a jovial crowd in the parking lot of Church of the Redeemer, a “Christian liberation community in the Episcopal tradition” in Morristown. Following a community dinner of home-cooked soul food and sweet-potato pie, Sister Simone and Sister Richelle Friedman take the stage in the altar of the church to record a podcast with the hosts of jesuitical, a podcast for millennial Catholics produced by America magazine.

Before the show starts, visitors, including many other nuns, take turns posing next to a “Nuns on the Bus” sign and taking selfies with big grins and thumbs up.

Of course, the crowds that greet them in Kingston, Morristown, and the other stops along their tour route are a biased audience. Many of the people who visit the tour are Catholic, interested in social justice, or both. Yet the sisters find a lot of value in that. “We have a lot of people coming to our events who you might call the choir, but actually often the choir needs encouraging as well,” says Sister Richelle.

So why do it on a bus? It’s a way of getting outside the institution and expanding the idea of what church means, on the sisters’ terms. “It could be a ferry,” muses Sister Simone. “Nuns on a Ferry.” It’s not the form that matters. “I find it all about the work of the Holy Spirit, alive and well and making mischief,” she says.