> The executive branch is the branch that controls military, FBI, CIA, BATF, US Marshals - the law enforcement agencies with guns, tanks and planes. Congress and the Courts don't have any similar enforcers.

military and law enforcement also swear an oath to uphold the constitution of the united states and to defend the nation against threats, including domestic ones. I think it's reasonable that they would defy a president who went totally off the rails to the point where he became a threat and violated the constitution.