who helped scuttle Trump's plans to cut a deal with Democrats in the summer of 2017 that would have traded deportation protections for immigrants who were brought to the U.S. illegally as children under the Deferred Action for Childhood Arrivals program for as much as $25 billion in funding for the border wall.

The White House quickly moved past that deal and made a counteroffer with a buffet of Miller policy favorites that were poison pills for congressional Democrats, including caps on legal immigration and an end to preferences for family members of immigrants who came to the U.S. legally.

In recent days, Trump has threatened to seal the border, drawing condemnation from economists and some prominent figures in his own party because of the potential cost to the economy;announced he will end foreign aid to Nicaragua, El Salvador and Guatemala even though that might lead to more migration from those countries to the U.S.; and publicly told asylum-seekers to "go home."

This past weekend, he told a Republican Jewish Coalition audience in Las Vegas that he was not interested in providing asylum to refugees.

"Our country is full, can’t come," he said. "I’m sorry."

Nielsen, who was a favorite of former Homeland Security secretary and former White House chief of staff John Kelly, was one of the administration officials who privately resisted, or only reluctantly embraced, policies built around hard-line positions like this.

Miller has survived them all. He's the only permanent fixture on immigration policy. That means he's running the show — and the president's success or failure is