Peter Navarro says Trump directed him to claim privilege in refusing Jan. 6 panel subpoena

Navarro faces contempt charges for defying subpoena from House committee investigating Capitol attack.
Navarro testified that Trump told him not to cooperate with the committee's investigation.
Navarro's defense claims Trump invoked executive privilege, but prosecution says that's unproven.
Judge expressed skepticism about strength of Navarro's defense arguments.
Navarro's case has implications for congressional authority and presidential reach.