Congress, and particularly the Democrat-controlled House of Representatives, seems determined to see the end of the Trump Administration before the 2020 vote. Although House Speaker Pelosi claims she is not seeking impeachment, she's accusing the president of "covering up" something. However, she won't say what until she can do more investigating.
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.