A team from the Cicero Institute, an upstart think tank, flew to Indiana this year to help make it a crime for homeless people to sleep on the street.

It was its third attempt. Even in the conservative state, previous efforts to ban street camping had failed. Catholic leaders said the measure would hurt the poor, and sheriffs had warned that arrests would crowd the jails. “We’re Hoosiers — we’re better than that,” a Republican state senator, Ron Alting, said last year, urging a more caring approach.

But much had changed since the group, founded by Joe Lonsdale, a billionaire ally of President Donald Trump’s, had made its initial efforts. Trump had issued an executive order on homelessness that so fully reflected Cicero’s agenda that it was hard to tell where the group stopped and White House policy began. The sponsor of the Indiana law was fresh from a Cicero conference; Cicero lobbyists worked the bill; and three Cicero analysts testified that the threat of arrests would push homeless people into treatment for mental illness or addiction.

The ban passed just before the legislature adjourned.

With homelessness near record levels, Republicans have embraced tough measures to clear the streets, and no group has led the way more than the Cicero Institute. Lonsdale formed the institute eight years ago with vague goals — to promote “liberty, accountability and transparency” — and no mention of homelessness. Now it has commandeered Republican homelessness policy.

Twenty-one states have considered camping bans or other Cicero-backed homelessness laws in recent years, and 16 have passed them. But the group’s sway goes further: It is working with the Trump administration to transform federal homelessness aid away from housing subsidies and toward the forced treatment of substance abuse or mental disorders.

Echoing Cicero’s thoughts and at times its very words, the administration says federal policy, called Housing First, neglects the root causes of homelessness by providing rental subsidies but leaving treatment optional. Opponents of Trump’s plan, which is blocked in court, say that forced treatment fails and housing aid gets people off the street.

Substantial evidence shows that Housing First succeeds in getting the chronically homeless housed, at least in the short term. But it is expensive, and the evidence also shows it has not consistently improved mental or physical health or lowered death rates. The treatment-first approach that Cicero favors has not been rigorously studied.

For many years, Housing First enjoyed bipartisan consensus; the first Trump administration took office embracing it. Cicero has helped make it a conservative epithet. “Obviously, our work has been one of the main influences” in shaping administration views, Lonsdale said in an interview.

The White House and the Department of Housing and Urban Development declined to comment on Cicero’s influence.

A co-founder of Palantir, a data-mining firm, Lonsdale, 43, is an unlikely force in homelessness policy. He brings to it vast wealth but no experience with homeless services and a distrust of conventional expertise.

Many on the left call Lonsdale an emblem of the inequality that creates homelessness — a billionaire fighting a reverse class war to preserve an unjust order.

“He’s using the homelessness crisis to deflect attention from the broken economic system that both causes homelessness and enables people like him to become billionaires in the first place,” said Jesse Rabinowitz of the National Homelessness Law Center, a progressive advocacy group.

Cicero first found success in Missouri, where a measure to create a camping ban succeeded as part of an unrelated bill the governor signed.

A win in one state — any state — built momentum. By the time the Missouri Supreme Court struck down the law on procedural grounds the following year, Cicero was on its way. Florida, Idaho, Kentucky, Louisiana, Mississippi, Oklahoma and Utah were among the states where camping bans followed.

The head of the group’s homelessness work, Devon Kurtz (who is based in Utah), 28, claims that camping bans save lives by encouraging treatment. That view has drawn retorts from many in the field, who say that there is no evidence to support it and that treatment is in short supply.

“It’s absurd to think that fining people will get them into treatment,” said Dr. Margot Kushel, a physician who directs the Benioff Homelessness and Housing Initiative at the University of California, San Francisco. “Many people are desperate for treatment and can’t get it.”

Since Trump cut Medicaid, which helps finance treatment, “it’s hard not to see the cynicism in this,” she added.

But Kurtz says many homeless people need the push that the threat of fines or arrest can provide. “They need that accountability; they need that supervision,” he said.

Though Cicero rose by focusing on states, Trump’s reelection expanded opportunity: Most homelessness policy and money come from Washington.

By congressional design, most of the $4 billion a year that the government spends goes to Housing First — long-term rental aid with voluntary treatment. Cicero wanted the opposite, temporary “transitional housing” (capped at two years) with treatment mandates.

During the campaign, Trump had released a seething video that pitted “dangerously deranged” people who “squat and do drugs” against “hardworking, law-abiding citizens.” Still, new policy was slow to emerge. Scott Centorino, who worked on homelessness issues at the White House Domestic Policy Council, later offered an explanation: The council wanted guidance from groups “in the trenches” like Cicero.

“We didn’t know what to do about it from a federal level,” he said at a closed-door Cicero conference in June, which an attendee taped. “We didn’t have somebody in our team, and I’ll include myself in this, who had a really strong grasp of what the federal authorities were in this space.”

In helping draft the executive order, he consulted with Cicero “to kind of bring you a sense of what the solutions might be.”

Asked about the comment, Centorino — who is now a Cicero Institute fellow — said that he also consulted with federal homelessness officials and other outside groups.

Ann Oliva, the CEO of the National Alliance to End Homelessness, an advocacy group, called the order “the most harmful policy proposal on homelessness in my career.”

A few months after the executive order, HUD issued an annual document called a Notice of Funding Opportunity. It had long been the lifeblood of Housing First, directing about 90% of homelessness aid to long-term housing. Following the principles in Trump’s order, HUD sought to move two-thirds of the money to time-limited programs with work rules or treatment mandates.

Lonsdale exulted.

“A lot of the permanent bureaucracy is in the hard left,” he said in an interview soon after. “We’re stopping them from doing it their way and forcing them to do it a different way.”

Opponents sued, arguing that only Congress could alter the program so profoundly and warning that as many as 170,000 formerly homeless people could lose housing. A federal judge blocked the initial plan and a revised version (which cited Cicero four times), both times on procedural grounds. HUD is appealing. In the meantime, the money has been dispensed under pre-Trump rules.

“Housing First has fueled a self-serving homeless industrial complex,” and “enabled dangerous encampments and addiction,” HUD Secretary Scott Turner said in a statement.

Dennis Culhane, a homelessness scholar at the University of Pennsylvania, contends the opposite, saying the problem is a shortage of Housing First funds.

He said the idea that homeless people do not need housing aid was “a radical assertion that runs contrary to experience and common sense.”

This article originally appeared in The New York Times.