If they didnโt return the passengers, they would be defying a court order, some administration officials worried. Miller, who is Presidentย Trumpโsย deputy chief of staff, pushed for the planes to keep flying, which they ultimately did. The judge would later say that allowing officials to defy court judgments would make a โsolemn mockeryโ of the Constitution.
The 39-year-old immigration hawk, who has been by Trumpโs side since the 2016 campaign, has emerged as a singular figure in the second Trump administration, wielding more power than almost any other White House staffer in recent memoryโand eager to circumvent legal limitations on his agenda.
He has his own staff of about 30 and a Secret Service detail, which White House officials said was because he had received death threats and serves as homeland security adviser. He has been responsible for the administrationโs broadsidesย against universities,ย law firmsย andย even museums. He has written or edited every executive order that Trump has signed.
Miller had considerable sway in Trumpโs first term. But when aides at the time suggested promoting Miller to a leadership role at the Department of Homeland Security, Trump declined, according to a former administration official, telling aides he thought Miller wasnโt leader material.
His influence has expanded sharply since, thanks largely to his steadfast loyalty to Trump. This account of Millerโs tenure is based on interviews with current and former White House officials, Trump advisers and other prominent Republicans.
Some of Millerโs colleagues said they were alarmed by some of the legal maneuvers that Miller has proposed for executing the administrationโs anti-immigrant agenda, and Trump has gently ribbed him for being too โhappyโ about deportations.
Miller, who isnโt a lawyer, is the official who first suggestedย using the wartime Alien Enemies Actย to deport migrants, which the Justice Department pursued. He also privately, then publicly, floated suspending habeas corpus, or the right for prisoners to challenge their detention in court, which the administration hasnโt tried. That prompted pushback from other senior White House and Justice Department officials.ย
Hisย orders to increase arrestsย regardless of migrantsโ criminal histories set off days of protests in Los Angeles. Miller coordinated the federal governmentโs response, giving orders to agencies including the Pentagon, when Trump sent in the Marines and the National Guard, according to officials familiar with the matter.
Millerโs portfolio covers almost every issue Trump is interested in. In recent months, he talked to CEOs about a coming tariff announcement;ย joined a meetingย betweenย Metaย Chief Executiveย Mark Zuckerbergย and Trump about the companyโs antitrust case; and met with other tech companies on artificial intelligence.
Even some posts at cabinet agencies have been described by administration officials as reporting directly to Miller, effectively bypassing cabinet secretaries.
There are some limits to his influence. He was supportive of Metaโs push to settle its antitrust case, which fell flat. Trump last week signaled concerns that the administrationโs deportation policies were too aggressive, calling for a pause in some deportations that he has since rolled back. Trump, asked how Millerโs directives on deportations squared with his own, declined to put distance between the two of them. โWe have a great understanding,โ Trump said.
The aggressive posture has started to sparkย some voter backlash, with polls showing Trumpโs approval rating on immigration and deportations has turned negative.
Several White House staffers said Miller always takes the most โextremeโ view of any issue, and his positions have cost the administration in court. In Trumpโs first 100 days back in office, courts issued nationwide injunctions in 25 cases against the federal government, compared with six in his entire first term and four during the Biden administration, according to aย reportย by the nonpartisan Congressional Research Service. Several cases have already reached the Supreme Court, which has ruled against Trump on some immigration cases.
โI think the administration has miscalculated and overstepped,โ said Skye Perryman, who leads Democracy Forward, an organization that has repeatedly sued Trump.
Miller has responded to the courtsโ intervention by denouncing it as โjudicial tyranny.โ His allies argue illegal border crossings are down to almost zero because his aggressive proposals are deterring migrants.
โStephen Miller is one of President Trumpโs most trusted and longest serving aides for a reasonโhe delivers,โ said Karoline Leavitt, the White House press secretary.
In the wilderness
Miller stuck by Trump when many staffers quit their jobs after the Jan. 6, 2021, attack on the Capitol. He had helped draft Trumpโs speech that morning, and worked until 12 p.m. on Jan. 20โthe day Trumpโs first term endedโtelling the officer taking his badge he would be back in four years.
โSixteen Hundred Pennsylvania Avenue is the greatest address in the world, and though we now leave these gates, rest assured, this is not goodbye,โ he wrote to colleagues.
Three months later, Miller launched a nonprofit, America First Legal, aimed at countering what Miller described as a โyears-long, one-sided legal assaultโ by the left. โNow, we must turn the tables,โ he said at the time.
Over the next four years, it filed dozens of lawsuits, many of which are ongoing, categorized on its website under topics including โDEI,โ โWoke Corporationsโ and โWomenโs Sports.โ The groupโs targets are now under fire from the Trump administration, too.ย
In 2022, the group called on the Education Department to stop distributing federal funds to universities where it alleged antisemitism was festering. Three years later, the Trump administration would do just that at universities including Harvard, Columbia and Northwestern.
In 2024, Millerโs group helped 16 Republican-led states sue the Biden administration over a policy that protected illegal immigrants married to U.S. citizens from deportation. A judge ruled in the statesโ favor, and the Trump administration overturned the policy this year.
By the time Trump returned to the White House, the group had about two dozen lawyers on staff and had raised more than $60 million from donors, whose identities it doesnโt disclose. The group paid Miller more than $500,000 last year, according to his financial disclosure.
Meanwhile, Miller continued to play an active role across the Republican Party, even if his outreach wasnโt always welcome.
Congressional aides fielded lengthy calls from Miller about illegal immigration, often without any specific requests. One likened him to a grandmother who wouldnโt stop talking and said his calls were akin to listening to a podcast. Others said he would call to scold aides about how they had framed a social-media post on a particular issue or criticizing the way they had worded a press release.ย
As a House committee prepared for then-Homeland Security Secretary Alejandro Mayorkas to testify, Miller came to the Hill to play the role of Mayorkas, aides said. During the prep, he answered questions as the secretaryโbut also chimed in to give lawmakers advice on questions.
Miller was determined to kill a bipartisan bill pushed by Republican Sen.ย James Lankfordย of Oklahoma in 2024 on the border and regularly called House Speakerย Mike Johnson.
He also called the Republican National Committee to offer his advice on how the party should communicate on immigration, sometimes offering his thoughts on what the RNC chairman could tweet, people familiar with the discussions said.
He was a regular visitor to Mar-a-Lago during the campaign, meeting with Trump above his ballroom. Campaign aides say Miller always wanted to talk more about immigration. Trumpโs top pollster,ย Tony Fabrizio, and his other aides wanted to keep the message on the economy. Trump staffers started displaying ominous photos of migrants at his events.
Hundreds of orders
In the first term, Trump was largely unprepared to govern. Miller regularly complained then that others in the administration tried to block his immigration decisions, and outside lawyers would stymie their efforts. This time, Miller came in determined to correct that.
He brought hundreds of proposed orders to the White House as well as his own staff.ย Russell Vought, the onetime treasurer of America First Legal, is now the White House budget chief. Reed Rubinstein, the groupโs senior vice president, was nominated as legal adviser of the State Department.ย Matt Whitaker, a board member, is the U.S. permanent representative to the North Atlantic Treaty Organization.
He now tells other staffers how to behave around Trump, people who have heard his comments say, and upgraded his office from one on a different floor to one steps from the Oval Office.ย
During the first term, Miller would push for hard-line policies that others blanched at, including advocating for several dozen countries to be added to the travel ban list of seven, a former administration official said. People laughed, but he was serious, the official said. This time, Trump announced a ban that coveredย a dozen countries.ย
He keeps in Trumpโs good graces by giving Trump ideasโbut more importantly, helping the president carry his own out.
Administration officials noted how Miller shut down discussion about whether the U.S. should bomb Houthi targets in a Signal chat that was accidentally shared with The Atlanticโs editor in chief. As the vice president and top national security officials discussed options, Miller weighed in.ย
โAs I heard it, the president was clear,โ Miller said. โGreen light,โ he added.ย
Earlier this month, Leavitt, the press secretary, interviewed Miller at a private event for Republican donors at the Four Seasons in Washington.
Miller, who grew up in Santa Monica, Calif., said large swaths of Los Angeles were engaged in a โrebellion,โ according to people present.
Los Angeles had become like Cancรบn, he saidโit was fine to visit, but not good for its own citizens. To conclude the event, Leavitt told the crowd that Miller needed to return to his work of deportations.
Miller smiled in response, and then left to return to the White House.
Write to Josh Dawsey atย Joshua.Dawsey@WSJ.comย and Rebecca Ballhaus atย rebecca.ballhaus@wsj.com