Stephen Miller slipped up on live TV with his use of the term plenary authority. While Trump is appealing the decision that troops cannot be deployed in Portland, Miller stated that they have plenary authority to deal with a specific situation .
Plenary authority is most commonly associated with Congress's broad, often absolute, power over certain issues, particularly immigration.
Miller and other Trump-affiliated figures have controversially used the term in the context of presidential power, arguing that the executive branch has near-absolute authority on some national security and immigration matters, which critics say would bypass normal judicial review.
This is not how the term was meant to be used. Plenary authority is used as a decision making process for the Legislative branch and not the executive branch’s innate right to bypass judicial decisions they do not like. That’s called authoritarianism.