Stephen Miller, the architect of President Donald Trump’s hard-line immigration policies, was noticeably absent from public view this week as the White House first vociferously defended and then caved on separating migrant children from their parents.

That wasn’t an accident. Among White House insiders, there is a sense that the president’s senior adviser for policy is a bad front man for the issue he’s most passionate about. Miller stayed entirely out of the spotlight during days of mounting political pressure, though behind the scenes he visited Capitol Hill on Tuesday night along with Trump to sell House Republicans on immigration legislation.

While other White House aides, like national security adviser John Bolton and National Economic Council director Larry Kudlow, are prized by Trump for their smooth defense of his policies on television, Miller is the opposite, valued as a source of ideas that the president believes appeal to his base. That includes not just the “zero-tolerance” immigration enforcement stance that triggered the family separations but the 2017 travel ban targeting visitors from predominantly Muslim countries, which generated a cascade of litigation for the young administration.