Over the past week, President Donald Trump doubled down on his openly racist attacks on four female minority congresswomen, repeatedly announced nationwide raids on undocumented immigrants, and had his administration roll out a new asylum plan—one that could very well be his greatest threat to migrants yet. And he’s done this all the while being validated, defended, and excused by numerous major players in the Republican Party, once again confirming his nationalist, immigrant-trashing grip on the GOP.

All together, it’s been a banner few days for the restrictionist, anti-immigration worldview of Trump and his top lieutenants who have encouraged the president to take a harder line on immigration since the early days of the campaign. Over the last few days, however, one man has been largely absent from the picture, the public tumult, and the cameras.

Stephen Miller.

Over the years, the 33-year-old senior policy adviser to the president has become virtually synonymous with the draconian immigration measures of the administration. He was a driving force behind the president’s brutal family-separation policy, one of the architects of Trump’s “Muslim travel ban,” constantly agitates against legal immigration levels and refugees, and serves as the top White House speechwriter. Even before he joined Trump’s team in January 2016, he was already proving key, serving, for instance, as the principal author of the campaign’s immigration “white paper” unveiled in August 2015.

As a member of President Trump’s inner circle, Miller’s hard-right influence, specifically on immigration policies, hasn’t abated. But his public and televised presence has stayed, for the most part, conspicuously muted. And that’s explicitly by design on Miller’s part.

As his profile has risen, Miller has become increasingly reclusive.

According to a senior White House colleague, Miller is very careful what he says on the phone, whether it’s to a fellow administration official or otherwise, in case the call is being recorded or could be used against him. Two other knowledgeable sources say that over the past two years, he’s cut off regular contact with most of his allies outside of the Trump administration and in advocacy groups because he wants to keep his circle of potential leakers as small as he can.

And Miller rarely does media appearances. His last major TV hit was in mid-February, when he went on Fox News Sunday to defend President Trump’s declared national emergency on the U.S.-Mexico border. In the West Wing, Miller is known for his laser-like focus on policy, and emphatic desire to operate behind-the-scenes and not become the story.

Those who have worked closely with Miller attest that he is adept at not infuriating the president, at least when it comes to hogging the limelight, a lesson he learned watching with a careful, calculating eye as Steve Bannon, Trump’s former top White House strategist, rose high within Trump’s orbit, only to be sidelined and denigrated by his boss after too many “President Bannon” media narratives. When Miller realized Bannon’s ouster was near, the senior policy aide turned on Bannon, his former ideological and personal ally, and started trashing Bannon in private conversations with Trump, tagging the strategist as a leaker and a destructive liability. His words helped hasten Bannon’s departure from the Trump White House.

Despite his desire to stave off a “President Miller” storyline, he has nonetheless emerged as a prime bête noire for liberal politicians and activists who hold him responsible for much of the human suffering caused under President Trump. According to two people who’ve spoken to him about this, Miller doesn’t at all mind that he’s routinely called a “Nazi” by critics and on social media, despite the fact he is Jewish.

“Sometimes he laughs it off, usually he just doesn’t give a shit,” said one senior Trump administration official.

“Stephen has ate, slept and breathed immigration policy for the past decade… and he’s the truest of true believers in Trump. So the President can always rest assured that Stephen’s going to execute on his wishes,” Cliff Sims, Trump’s former director of White House message strategy, told The Daily Beast. The two have known each other going back to Miller’s days working in then-Sen. Jeff Sessions’ (R-AL) office when Sims ran an Alabama-based news organization.

“The handful of times he’s been public-facing have been as over-the-top as possible in his defense of Trump and advocacy for his policies,” Sims added. “But ultimately he prefers to just keep his head down and work behind the scenes. That’s when he’s most effective.”

One way in which Miller has continued to expand his grip on power and influence in the Trump era is through the Department of Homeland Security. Earlier this year, Miller successfully lobbied the president to oust multiple senior officials deemed “weak” or insufficiently ruthless on the immigration agenda. This included Kirstjen Nielsen, the former homeland security secretary, who for a year and a half was engaged in a bitter cold war of paranoia and backstabbing with Miller.

His word carries weight with the president, so when Trump was looking to fill a top position earlier this year, Miller was among the senior officials who endorsed Ken Cuccinelli in discussions with the president.

In Cuccinelli, Trump’s newly installed acting director of Citizenship and Immigration Services (USCIS), a DHS agency, Miller has found a new reliable ally. The senior White House aide and Cuccinelli see eye-to-eye on issues related to asylum seekers and slashing legal immigration, and Miller is known to proactively call Cuccinelli and his team for regular updates, said a source with knowledge of their relationship. When Trump was looking to fill the role of acting director earlier this year, Miller was among the senior officials who endorsed Cuccinelli in discussions with the president.

Indeed, Cuccinelli is merely the latest high-profile example of DHS continuing to be stacked with what some career government officials have privately derided as “mini-Millers.” Or, as one White House official described it, “when Cuccinelli talks or acts [nowadays], pretend you’re looking at or listening to President Trump or Stephen Miller… It’s the same thing.”

In his current role, Cuccinelli appears to be less camera-shy than his fellow administration hand Miller. John Cohen, a former senior official at DHS in the Obama administration, said it was “unusual” for the head of USCIS to spend time on national television talking about ICE activities, as Cuccinelli did this month.

“In my day, if we had a situation that we were confronting at southern border and we had a dramatic increase in persons requesting protection through asylum, the head of USCIS would be one of the loudest advocates for surging resources to the border...so those claims can be made,” Cohen said. “I haven’t heard much of anything coming from USCIS about how they are going to address the dramatic increase of these people.”

Over the last several days, the Trump administration said it would deploy additional resources to ICE field offices to support their investigative or deportation operations. Cohen said those resources are being diverted—under Cuccinelli’s watch—away from USCIS employees who are processing asylum claims.

It also happens to be an outcome Miller prefers, according to two sources familiar with the situation.

“That has got to be one of the most misguided things I’ve heard in the last several years,” Cohen said. “USCIS should be expanding their resource base so they can effectively address the surge at the southern border.