Declare them AN ENEMY OF THE PEOPLE
Take away their citizenship
Exile them to someplace else
Imprison them with an open ended time of release up to and including NEVER
Have them killed
This is what despot dictators do all the time. People dare not speak truth to power. They dare not speak up against the power. In every case the power will win.
So if TGITWH successfully strips his "enemies" of their security clearances doesn't that open the gate for him to retaliate against whomever whenever however he chooses? Who will stop him? At what point?