From New Republic:

Ex-officials stress that Trump, like other authoritarian figures, has displayed a penchant for ousting officials who don’t adhere to his political whims and dictates. “Trump is fundamentally about self-interest,” Paul Rosenzweig, a former senior DHS official and ex-prosecutor for the Department of Justice, says. “He has, slowly but surely, bent the government to his service.”

Rosenzweig notes that Trump’s initial set of premier Cabinet officials, such as Attorney General Jeff Sessions, Defense Secretary James Mattis, and DNI head Dan Coats, “were strong actors who resisted his greatest excesses.” Once Trump sent them packing, he made a point of recruiting die-hard loyalists in their stead. Their replacements, Rosenzweig says, are “all sycophants who would never dare to cross him.”