In case there were any doubts over his White House standing, Stephen Miller offered his critics the ultimate power move Tuesday as he boarded Air Force One to accompany President Trump to a campaign rally in South Florida.

Miller’s reserved seat was another sign that the White House senior adviser has suffered no internal consequences in the two weeks since a social justice website published a trove of his old emails that showed him promoting political material and talking points linked to white-supremacist groups.

The disclosures in the exposé from the Southern Poverty Law Center have prompted scores of Democratic lawmakers and civil rights groups to publicly demand his resignation over what they view as smoking-gun evidence that the Trump administration’s hard-line immigration policies are rooted in white nationalist ideologies.

But the White House has vigorously defended Miller, one of Trump’s longest-serving and most influential aides, and congressional Republicans are staying mum, signaling that they will not break with the president over the revelations at a time when Trump is eager to demonstrate momentum in stemming illegal immigration.

“If Republicans did not distance themselves from Trump after Charlottesville, they are not going to distances themselves over leaked emails by a staffer sent before Trump was elected president,” said GOP strategist Alex Conant, a former aide to Sen. Marco Rubio (R-Fla.), referring to the president’s remark that there were “very fine people on both sides” of a deadly white supremacist March in Virginia in 2017.

Much of the anti-immigration views that Miller promoted in his private correspondence with a reporter at the far-right Breitbart News during Trump’s presidential campaign in 2015 and 2016 reflected views that Miller, who had served as an aide to Jeff Sessions (R) when Sessions was a U.S. senator from Alabama, had promoted for years in meetings with lawmakers, Conant added.

“The more controversial positions such as why immigrants are bad for American culture — that’s what he believes, and a lot of that is what the president believes, too,” Conant said. “Those are arguments he made in rooms with other Senate staffers. It’s not a surprise at all.”

Indeed, Miller’s track record as a key architect of many of the Trump administration's most controversial immigration policies — including a ban on travelers from majority-Muslim countries and punitive actions against immigrants who receive public assistance — have in a sense inoculated him from attacks from fellow Republicans over his emails.

Late last week, two dozen Senate Democrats, including Minority Leader Charles E. Schumer (D-N.Y.), joined more than 100 in the House in calling for Miller to step down, according to a survey by HuffPost. The chairs of House caucuses representing racial minorities and progressives issued a joint statement calling Miller a “white nationalist,” and more than 50 social justice groups signed an open letter to Trump accusing Miller of “stoking bigotry, hate, and division.”

But former U.S. immigration officials said the Trump administration’s relentless efforts to limit virtually all forms of immigration — including tightening controls on refugees, foreign students and other legal immigrants — have shifted the Republican consensus on the issue.

The president has used immigration to help to maintain a tight grip on the GOP base, and Republican lawmakers, even those who have supported more-moderate positions, have been reluctant to oppose him.

“In every previous administration, if such allegations were to come out about a senior staffer at the White House, they would probably be terminated,” said Theresa C. Brown, an analyst at the Bipartisan Policy Center who served as a career immigration policy official at the Department of Homeland Security before leaving in 2011. “And yet I don’t think anybody expects that to happen here, which just demonstrates the ways in which our political norms have changed.”

The SPLC said its reports were based on hundreds of Miller’s emails provided to the organization by Katie McHugh, a former Breitbart staffer who collaborated with Miller on stories during the campaign.

The emails illuminate Miller’s fixation on crimes committed by immigrants and people of color, as well as his eagerness to push narratives sourced from fringe white supremacist and conspiracy-theory websites such as VDARE and Infowars.

Miller touted story lines that echoed the far-right vision of “white genocide” — the extremist belief that immigration from nonwhite parts of the world poses an immediate and existential threat to the racial integrity of white people, a belief that has motivated the shooters behind a number of far-right terrorist attacks in recent years.

White House press secretary Stephanie Grisham denounced the SPLC as a “far-left smear organization,” and her deputy Hogan Gidley, citing Miller’s Jewish heritage, said Miller “loves this country and hates bigotry in all forms.”

Republicans have largely avoided the matter, declining to comment on the disclosures. In one story, the SPLC reported that Miller targeted Trump’s 2016 opponents for the Republican presidential nomination. He most frequently attacked Rubio, who had supported a bipartisan immigration bill in 2013, calling him “an extremist who wants unlimited immigration” and disparaging him as dishonest to the point of being “pathological.”

“I knew at the time he wasn’t a big fan of mine” Rubio told reporters last week when asked about the report. But the senator and his aides have otherwise declined to comment about the other disclosures in the SPLC series.

The email disclosures are likely to further damage the ability of the White House and Democrats to negotiate changes to U.S. immigration policies that both political parties have agreed are outdated and insufficient for present needs.

To deal with a massive surge in the number of undocumented migrants over the past year, the White House has focused on using executive powers to speed up deportations and curtail the ability of migrants to seek asylum at the border. Administration officials have touted a large drop in border apprehensions since they reached a 12-year high in May. But Democrats have resisted Trump’s demands to tighten legal restrictions on asylum, saying the administration cannot be trusted to negotiate in good faith.

“From an optics perspective, I do think it complicates negotiations with the Hill in terms of finding middle ground or compromise,” a former Trump administration official who worked on immigration issues said of Miller’s emails.

Domingo Garcia, the president of the League of United Latin American Citizens, has met with other White House officials over immigration policy, including senior White House adviser and Trump son-in-law Jared Kushner. Garcia has remained hopeful that a compromise can be worked out over the fate of younger undocumented immigrants known as “dreamers.”

But Garcia called Miller “a major impediment to getting a bill done, based on views that those emails highlighted as someone with extremist, anti-immigrant views. In no way can you negotiate with someone who has that kind of mind-set.”

Ishaan Tharoor contributed to this report.