This post has been updated. 6:20 p.m.

President Trump keeps warning that undocumented immigrants will increase unemployment among native-born Americans. There was scant evidence of this prior to Sunday, but it is now an undeniable fact. The surge in apprehensions along the southern border (more than twice as many arrivals arrested in February 2019 compared with February 2018) just cost Kirstjen Nielsen her job.

It is almost comical to see how little credit the now-former homeland security secretary received from her abusive boss for sacrificing her reputation and humanity on his behalf. She tried oh-so-hard to win “The Apprentice: White House Edition,” but all she got in return was: “You’re fired!”

She gamely denied that the Russians had interfered in the 2016 election to help elect Trump, even though the intelligence community had concluded that they had. She defended Trump’s inexcusable defense of white nationalists at Charlottesville, insisting that “it’s not that one side was right and one side was wrong.” Worst of all, she enacted the barbarous policy of separating children from their migrant parents, while denying that she was doing so.

It was never enough. Nielsen may have been willing to violate the dictates of morality, but she wasn’t willing to actually break the law. The New York Times reports that “the president called Ms. Nielsen at home early in the mornings to demand that she take action to stop migrants from entering the country, including doing things that were clearly illegal, such as blocking all migrants from seeking asylum. She repeatedly noted the limitations imposed on her department by federal laws, court settlements and international obligations.”

The Post reports that “she appeared to regain her footing after U.S. Border Patrol agents used tear gas to repel a large crowd attempting to break through a border fence — the kind of ‘tough’ action Trump said he wanted in a DHS secretary.” But the points earned for gassing women and children were insufficient to save Nielsen’s job. Trump demanded more and more. In California on Friday, CNN reported via Twitter, “Trump told border agents he wanted them to stop letting people cross the border, despite the fact that Central American asylum seekers according to U.S. law can do so.”

Someone had to be blamed for Trump’s failure to control the border, and Nielsen made a convenient scapegoat, along with Ronald D. Vitiello, whose nomination to head Immigration and Customs Enforcement was withdrawn on Friday. It is, of course, impossible to imagine that Trump could rethink his counterproductive approach to border security rather than simply shuffling the individuals implementing it. He is not capable of questioning whether a border wall makes sense, given that most illegal immigrants arrive by airplane and then overstay their visas — or the fact that Central American migrants are not sneaking across the border but turning themselves into U.S. authorities to claim asylum.

Perversely, Trump has just eliminated one of the few programs to show any effectiveness in reducing the flow of Central American migrants. As the Post notes, “In the past three years, both El Salvador’s homicide rate and migration flows have declined sharply. More than 72,000 Salvadorans were apprehended crossing the U.S. border in 2016. By 2018, the number had plummeted by more than half, to fewer than 32,000.” Yet, in a fit of pique worthy of a mad king, Trump abruptly canceled $500 million in U.S. aid for El Salvador, Honduras, and Guatemala, thereby exacerbating the very problem he is so exercised about. But hey, at least he saved about one-hundredth of one percent of the federal budget.

It is time to end the charade. Trump is agitated that Nielsen was not barbarous enough for his depraved tastes. She still retained some vestigial loyalty to the Constitution and the laws of the United States. Given that we are in a time of purported emergency, we can no longer afford such sentimental attachments. Rather than appoint another outsider who will never live down to his expectations, Trump should nominate as her successor the actual mastermind of the administration’s immigration policies: White House senior policy adviser Stephen Miller.

This is the 33-year-old wunderkind who orchestrated the Muslim travel ban, vast reductions in refugee admissions, efforts to build the wall, attempts to deport the "dreamers," the deployment of troops to the southern border, and, of course, the family separations policy — along with the accompanying hysteria about crimes committed by undocumented immigrants. He even went so far as to deny that the Emma Lazarus poem inscribed on the Statue of Liberty — "Give me your tired, your poor, Your huddled masses yearning to breathe free” — represents the spirit of America. Miller has further ambitions such as ending “birthright citizenship” and slashing legal immigration. He should assume formal, legal responsibility for this un-American approach.

Stop trying to put a civilized face on an uncivilized policy. Trump should have the courage of his racist convictions: nominate Miller as secretary of homeland security and let the puppetmaster come out from behind the curtain. Or is Trump afraid that even a Republican-controlled Senate wouldn’t confirm this nativist fanatic? Miller may well be judged too radioactive because he eschews the “white lies” favored by Nielsen and her predecessor, John F. Kelly. If an honest defense of the administration’s heartless and vindictive approach to immigration won’t survive the light of day, perhaps that should be an indication to the president that the real problem is not personnel but policy.

Read more:

The Post’s View: Why Trump’s ‘help wanted’ administration erodes public service

Erik Wemple: Lou Dobbs and Fox News: Trump’s immigration lunatic fringe

Greg Sargent: Kirstjen Nielsen just revealed how Trump’s pathologies and lawlessness will get worse

Jennifer Rubin: Kirstjen Nielsen’s legacy of cruelty and incompetence is sealed

The Post’s View: Kirstjen Nielsen’s season of cruelty and futility

Fareed Zakaria: If Trump’s new immigration stance is here to stay, it could lead to powerful compromise