border threatens to create a crisis in competence for his administration.

If illegal immigration was a problem before Trump took office, it has become worse — not better — since then, and he is looking for scapegoats. Nielsen, disliked by the right for opposing some of Trump's harshest tactics, and by the left for becoming the public face of unpopular policies like separating children from their parents as a means of deterring future immigrants, was a convenient fall woman.

Her departure comes as Trump is turning hard toward the Miller playbook, which is full of take-no-prisoners policies and rhetoric that demonizes immigrants. If Trump is unable to bend Congress, his own administration, other countries and immigrants to his will, he'll be sure to tell his immigration-obsessed base that he onlyfailed because he didn't have enough power. And he'll ask for more in the form of another term, more Republican members of Congress and the ability to appoint a new slew of conservative judges to federal courts.

That's the Miller way, and Trump has little choice politically but to follow it after alienating liberals and moderates with his immigration policy so far.

His re-election strategy depends on locating Americans who agree with him but don't usually vote and driving them to the polls in droves. That, he has clearly concluded, means taking the hardest possible line on immigration and presenting it primarily as a security issue, even if there is a legitimate humanitarian crisis playing out at the border now.

It was Miller, the Duke University-educated senior policy adviser, now 33,