In the authoritarians handbook, there is the notion of a shock event, and event that rallies the public against a perceived injustice. The authoritarian pushes through a change, and intentionally makes it 20% harsher than what he wants. Everyone is horrified, mass protests begin, eventual the president relents and removes the 20%. Everyone goes home feeling that they have accomplished something good, and the leader has achieved his aim. While the public outrage is going on, he usually slips through some other change that he wants to have less notice.
The first shock event was banning Muslim immigrants from 7 predominantly muslim nations, including anyone with a valid visa, and all green card holders. People whose only home is in America where held in detention, and denied entry, even though they had already been vetted, and were legally allowed to be in the country.
There were massive protests, and eventually Sally Yates, the acting Attorney General, was fired and replaced with a presumably more pliable minion.
The main effect of this action was to start the protest, find out who in the government was going to follow an illegal order and who wouldn't, and to then purge those who would put country ahead of the president. At the same time as the muslim ban was put into effect, Steve Bannon was added to the National Security Council, and the Chairman of the Joint Chiefs of Staff, and the Director of National Inteligence were removed.
