WASHINGTON — Stephen Miller was furious — again.
The architect of President Trump’s immigration agenda, Mr. Miller was presiding last month over a meeting in the White House Situation Room when he demanded to know why the administration officials gathered there were taking so long to carry out his plans.
A regulation to deny welfare benefits to legal immigrants — a change Mr. Miller repeatedly predicted would be “transformative” — was still plodding through the approval process after more than two years, he complained. So were the new rules that would overturn court-ordered protections for migrant children. They were still not finished, he added, berating Ronald D. Vitiello, the acting head of Immigration and Customs Enforcement.
“You ought to be working on this regulation all day every day,” he shouted, as recounted by two participants at the meeting. “It should be the first thought you have when you wake up. And it should be the last thought you have before you go to bed. And sometimes you shouldn’t go to bed.”
A few weeks after that meeting, the consequences of Mr. Miller’s frustration and the president he was channeling have played out in striking fashion.
Mr. Trump has withdrawn Mr. Vitiello’s nomination to permanently lead ICE and pushed out Kirstjen Nielsen, his homeland security secretary. The department’s acting deputy secretary, Claire Grady, and the Secret Service director, Randolph D. Alles, are departing as well. And the White House has made it clear that others, including L. Francis Cissna, the head of United States Citizenship and Immigration Services, and John Mitnick, the department’s general counsel, are likely to go soon.
Mr. Trump insisted in a tweet on Saturday that he was “not frustrated” by the situation at the border, where for months he has said there is a crisis that threatens the nation’s security. But unable to deliver on his central promise of the 2016 campaign, he has targeted his administration’s highest-ranking immigration officials.
And behind that purge is Mr. Miller, the 33-year-old White House senior adviser. While immigration is the issue that has dominated Mr. Trump’s time in office, the president has little interest or understanding about how to turn his gut instincts into reality. So it is Mr. Miller, a fierce ideologue who was a congressional spokesman before joining the Trump campaign, who has shaped policy, infuriated civil liberties groups and provoked a bitter struggle within the administration.
White House officials insisted to reporters last week that they had no choice but to move against administration officials unwilling or unable to make their agencies produce results. One senior administration official at the White House, who requested anonymity to discuss what he called a sensitive topic, said many of the administration’s core priorities have been “either moving too slowly or moving in the wrong direction.”
But current and former officials from those agencies, who also requested anonymity to discuss contentious relations with the White House, describe a different reality.
The purge, they said, was the culmination of months of clashes with Mr. Miller and others around the president who have repeatedly demanded implementation of policies that were legally questionable, impractical, unethical or unreasonable. And when officials explained why, it further infuriated a White House set on making quick, sweeping changes to decades-old laws.
In a twist, many of the officials who have clashed with the White House were the president’s own political appointees, who share his broad goal of limiting immigration into the United States. To that end, they have already succeeded in lowering the number of refugees allowed into the United States, imposing a travel ban on entry from mostly Muslim nations, speeding up denaturalization proceedings, slowing asylum processing at ports of entry and developing proposals to limit work permits for spouses of high-tech workers.
“I don’t think the president’s really cleaning house,” said Thomas D. Homan, a former acting ICE director and strong supporter of the president’s immigration agenda. “I think he’s setting the reset button.”
A White House spokesman declined a request for comment. But even several of the most right-wing, anti-immigration groups have had a mixed reaction to the treatment of the immigration officials Mr. Trump and Mr. Miller have targeted.
The Center for Immigration Studies tweeted that “Nielsen got tough at the end of her tenure, but it was largely too little, too late.” The Federation for American Immigration Reform wrote: “Under Francis Cissna’s leadership, USCIS has issued a steady stream of policy changes and regulations that are firmly in line with President Trump’s immigration agenda. Removing him would be a huge mistake.”
But it has not been enough for Mr. Miller and his allies in the White House feeling the constant pressure from Mr. Trump.
Perhaps the greatest point of contention within the administration has been the asylum laws that are the root cause of the most vivid manifestation of the immigration issue: the hundreds of thousands of migrant families from Central America who have surged toward the southwestern border, fleeing violence and poverty.
In a Tuesday afternoon “deputies” conference call last year with about 50 or 60 officials from across government, Mr. Miller demanded to know why nearly all of the families seeking asylum were passing the first hurdle — a screening interview to determine whether they have a “credible fear” of persecution if they were returned to their home countries.
Mr. Miller and others in the White House were outraged that 90 percent or more of the applicants passed the first screening, a concern during the Bush administration, as well. Immigration judges ultimately deny all but about 20 percent of the asylum requests, but because of a backlog of hundreds of thousands of cases, many asylum seekers wait years for their case to be heard for the second time, giving them the chance to gain work permits, build roots and disappear in the United States.
To Mr. Miller, the asylum process was a giant loophole that needed to be plugged. And he faulted the asylum officers at Citizenship and Immigration Services who were conducting the screenings for having a cultural bias that made them overly sympathetic to the asylum seekers. “You need to tighten up,” Miller insisted.
Immigration officials on the conference call did not disagree that too many migrants were granted asylum in the initial “credible fear” screening. But the rules for conducting the screenings were written into law by Congress and designed to be generous so that persecuted people had a real opportunity to seek asylum. It was unclear, the officials said, what else the agency could do.
Listening to Mr. Miller continue to hammer the issue, two people on the call recalled, it was almost as if Mr. Miller wanted asylum officers to ignore the law. At one point during the call, Mr. Cissna erupted in frustration.
“Enough. Enough. Stand down!” he said.
But such pressure from the White House was hardly unique, according to officials from multiple agencies.
For instance, a federal judge last week ruled that the White House early in the administration had improperly pressured officials at Citizenship and Immigration Services to terminate an immigration program for Haiti called Temporary Protected Status.
The judge said the decision in 2017 to end the program was contrary to the statute and indicated that the White House had strongly influenced the department.
More recently, White House officials pushed during one of the Tuesday afternoon conference calls to have Border Patrol agents, instead of asylum officers, conduct “credible fear” interviews. The notion, they said, was that the Border Patrol agents could process interviews quickly and cut out the several-day wait to schedule a meeting with an asylum officer.
Many of the immigration officials recoiled at the idea. Assigning agents to interview duty would pull them from their primary roles at the ports and along the border. Even worse, asylum laws require interviewers to undergo up to two months of training that would strain the already understaffed Border Patrol stations.
But even if they could be trained, officials told the White House, the logistics would be a nightmare. Cramped Border Patrol stations — many of which look like small, rural police stations — were not set up to conduct scores of two-hour interviews with hundreds of migrants flooding into border communities each day.
When the idea leaked out in early April, immigrant rights advocates accused the Trump administration of trying to prevent migrants from having a real chance at asylum.
“Border Patrol officers are simply not qualified to do this,” said Eleanor Acer, the director of the refugee program at Human Rights First. “This will put unfit, untrained and unqualified agents in charge of determining who warrants potentially lifesaving protection in the United States.”
To Mr. Miller and other White House officials, it was another instance in which the law and machinations of government were getting in the way of needed changes. And they think there are many others.
In November, as Mr. Trump railed publicly about the dangers of migrant caravans from Central America, a top White House domestic policy adviser floated the idea of taking migrants who had been apprehended to so-called sanctuary cities represented by Democrats. Homeland security officials, who saw the idea as political retribution, resisted.
In an email, Matthew Albence, the acting deputy director of ICE, said that it would create “an unnecessary operational burden” and that transporting the migrants to a different location was not “a justified expenditure.” Lawyers at the Department of Homeland Security, including Mr. Mitnick, also questioned the idea’s legality.
The idea was dropped until last week, when news stories about the rejected proposal prompted Mr. Trump to say his administration was still considering the option.
Mr. Trump has also not given up on the idea of shutting down the southern border, a move economists have said would be catastrophic and halt nearly $1.7 billion of goods and services that flow across the border each day.
Even as Mr. Trump retreated publicly and said he would give Mexico a year to do more to prevent migrants from reaching the southern border of the United States, he has made it clear to his advisers privately that the closing was still on the table.
His insistence increased the friction with his top immigration officials, especially Ms. Nielsen, who tried to talk him out of closing the ports of entry and refusing to grant asylum. Ms. Nielsen explained why she could not do that, citing economic and legal issues — banning migrants from seeking asylum would be against the law.
When Ms. Nielsen did not give the president the answer he sought, he turned to Kevin McAleenan, the commissioner of Customs and Border Protection, and asked him to stop migrants from entering the country. Mr. Trump told Mr. McAleenan that he would pardon him if he ran into any legal problems, according to officials familiar with the conversation — though he denied it in a tweet Saturday night.
Ms. Nielsen’s refusal to shut down the southern border appeared to be the final straw for Mr. Trump. After forcing her resignation, he named Mr. McAleenan the acting secretary of the department.
But Mr. Miller remains unsatisfied. Lately, he has made clear to immigration officials and others in the White House that he remains frustrated with the still-pending regulation on welfare benefits for immigrants. After nearly two years of painstaking work and more than 200,000 public comments, the 447-page rule is on track to eventually be published.
And it is not clear that the political bloodletting is over. Mr. Cissna and Mr. Mitnick remain in bureaucratic limbo, having received neither their walking papers nor an explicit stay of execution. While Mr. McAleenan is now the acting secretary of homeland security, rumors persist that Mr. Trump may want someone else to be the permanent head of the department.
Inside the immigration agencies, there is a persistent rumor that Mr. Trump may yet name an immigration czar to better coordinate — or, some believe, control — the sprawling immigration bureaucracy.