Stephen Miller "was running a sort of secret immigration think tank out of the West Wing," the N.Y. Times' Julie Davis and Mike Shear report in "Border Wars: Inside Trump's Assault on Immigration," out Tuesday.
An excerpt from the book says that the group, which usually met on Fridays, was part of "a quiet but methodical effort...to seize control of the machinery of government and use it to make good on the president's immigration agenda."
As Think Tank Watch has previously noted, Miller is likely the largest consumer of think tank reports in the entire White House.
Here is a previous post about another internal White House think tank in the Trump era.