As we enter the last 22 months of President Trump's first (and possibly last) term, one thing is certain: Trump believes that his extreme immigration policy, which continues to rip apart mostly Central American families and other asylum seekers, will be the determining factor in whether he sees a second term.

And in an administration that continues to redefine how right to the right an American presidency can be on immigration, the Sunday resignation of Homeland Security Secretary Kirstjen Nielsen proved that the country's most extreme anti-immigration nationalists, with the ear of White House Senior Adviser Stephen Miller, has officially taken over the administration's agenda. (Miller not only played a reported role in Nielsen’s resignation, but is also calling for changes to be made at U.S. Immigration and Customs Enforcement and the United States Citizenship and Immigration Services.)

Customs and Border Protection Commissioner Kevin McAleenan might become the new acting secretary, but it is Miller who is reportedly calling the shots. In the eyes of Miller and his anti-immigration allies, Nielsen wasn't tough enough to follow through on what is perhaps the most inhumane immigration enforcement plan of the last 30 years — despite the fact the Nielsen had defended family separations, has pushed for a "Remain in Mexico" policy that essentially denied asylum seekers the legal right to seek asylum in the U.S. and insisted that immigration was our country's biggest national security issue (it is not).

Trump (and very likely Miller) believe that the only way to stop the "invasion" is to go back to a family separation policy that was blasted for its cruelty, condemned by federal courts for being un-American and ended through an executive order by Trump himself. That is apparently where Nielsen drew the line.

Nobody should be shocked that McAleenan was Trump's pick for acting DHS secretary; he's reportedly suggested that making family separation the parents' choice could enable the government to reinstitute the policy. He also insisted just last week that CBP could no longer handled migrants seeking asylum, though U.S. law requires that be an option for migrants. And under McAleenan, we have seen the literal caging of migrants, the in-custody deaths of children, the use of tear gas at the southern border and the insistence that any crisis was absolutely, definitely not a foreseeable result of CBP slowing down asylum claims and shutting down ports of entry.

The country is “full,” as Trump said last Friday in California, while claiming that Central American families fleeing violence and poverty are making up their stories, further dehumanizing their lives. (He also suggested that border agents simply defy judicial rulings to further his agenda.) That push to limit immigration and create a false myth of a “full” country has roots in an anti-immigration establishment that reveres Miller as its conquering hero.

That cabal, under quasi-intellectual names such as the Center for Immigration Studies, Numbers USA and the Federation for American Immigration Reform, has long lamented that the newest waves of immigrants are only making our country poorer, browner and dumber. They used to be so fringe, but their ideas have of late earned the praise of conservative think tanks like the Heritage Foundation, once a proponent of actual comprehensive immigration reform, as well as Rep. Steve King, R-Iowa, and Senator-turned-Attorney General Jeff Sessions, whom Miller served on Capitol Hill. Acceptance by establishment conservatives meant their ideas got more and more traction — so much so that Trump’s immigration platform from his 2016 campaign was taken right out this anti-immigration playbook.

And those inroads have given them a pipeline to the White House: One former FAIR employee told me last year that his organization would have direct calls with the White House and that Miller was part of that conversation.

In other words, an unelected aide not subject to Congressional confirmation has essentially been put in charge of White House immigration policymaking and enforcement, for a president that is encouraging law enforcement to ignore the law in an effort to bar terrified families from legally seeking asylum, all in deference to a secretive policy establishment broadly funded by wealthy Republicans.

There is no doubt that the Trump base will continue to praise the tough talk and tougher actions, and that anyone who speaks out against will be labeled as a socialist in favor of open borders. The myth of the criminal migrant was a winner in 2016 and clearly Miller and Trump think it can work the same way in 2020. But they can't keep shouting "Build the wall" when no wall is getting built;they will inherently have to go to greater extremes to keep appealing to their anti-immigrant base and thedonors funding it — even if it more and more migrants suffer. After all, he has a second term to win.