What if lying, the denial of reality, is just a self-protective defensive response to psychological abuse? If so, then the intent is not to deceive, but to protect.
That might explain Sarah Sanders. Perceiving herself to be in enemy territory, she lies. If so, I would argue that habit did not just suddenly develop in the White House. Rather, she brought it with her from home and it has enabled her to persist in an environment others would not condone.
Stepford Daughters all have that same lifeless expression. For that matter, Jared Kushner has it too.