“Fate,” Arpaio told me, binds him to Trump. They share a gut-level instinct for law-and-order politics, if not for the rule of law itself, and an ability to parlay the resentments of white voters into electoral success. Last summer, Arpaio, the famous jailer, faced incarceration himself. A federal judge convicted him of criminal contempt of court for his “flagrant disregard” of an order to stop detaining people solely on suspicion of their being in the country illegally. As Hurricane Harvey bore down on southeast Texas, Trump found time to pardon Arpaio.

In recent interviews, immigration restrictionists, immigrant advocates, and former Immigration and Customs Enforcement officials found a point of common agreement. For better or worse, they said, pardoning Arpaio sent a clear message to immigration agents: take the gloves off.

“Pardoning Joe Arpaio sends a very clear message to ICE agents,” said Kevin Landy, a former assistant director at ICE. Agents now understand they need not be “overly concerned about individuals’ due process rights,” Landy lamented. The pardon is a “green light” for racial profiling, worried Carlos Garcia of the Phoenix-based advocacy group Puente. Jessica Vaughan, an analyst at the Center for Immigration Studies, which supports restrictive immigration policy, approved of the pardon because it telegraphs “no apologies for increasing immigration enforcement,” even if it is “politically incorrect.”

Arpaio lost reelection in 2016, and the new Maricopa County Sheriff promptly shut down his notorious jail. But with Arpaio’s brand of toughness now embodied in Trump’s crackdown on immigrants, his legacy extends far beyond the rows of surplus tents left over from the Korean War. Arpaio said that Trump removed the “handcuffs” from immigration agents. At last, he said, “they can enforce the illegal immigration laws.”

The United States has built an archipelago of more than 200 immigration-detention centers, sprinkled throughout the country. ICE keeps immigrants in detention when the agency determines they are a flight risk or a threat to public safety. Most are held for days or weeks en route to deportation, but thousands are confined for years while they fight their removal. Detainees are not serving a criminal sentence, but the conditions in detention are often indistinguishable from those of a prison.

“Under the Trump administration, we’re seeing the detention system balloon,” said Clara Long, a senior researcher at Human Rights Watch. With arrests up by 30 percent, ICE has requested $2.7 billion to increase detention capacity by 25 percent. “It is one of the fastest growing sectors of the carceral state,” said Kelly Lytle Hernandez, an immigration historian at UCLA.

Detention is big business. ICE relies on private prison companies for roughly 70 percent of its long-term lockups. After the election, the stock prices of the two largest private prison companies, Geo Group and CoreCivic, nearly doubled.