But Trump's opponents on both sides of the Congressional aisle don't seem so enthusiastic about challenging the president when he actually does abuse his Constitutional authority to pursue a more aggressive policy overseas.

Late last week, for example, President Trump declared a national security "emergency" brought about by unspecified "Iranian malign activity" – a "loophole" allowing him to bypass Congressional review of some $8 billion in US weapons to be sold to Saudi Arabia.

Congress had been reluctant to approve yet more arms sales to Saudi Arabia after the President vetoed a bi-partisan House and Senate-approved bill requiring the US to end its military support for the Saudi war of aggression against Yemen.