By definition, the Executive branch executes orders. Whose orders?
Not the population.
Not the Congress.
Not the Supreme Court.
Answer is the military.
The Constitution was designed by people accustomed to the English monarchy. Whether subconsciously or consciously, it pre-supposed a monarch to deliver the orders. The military (and in some respects lawyers) have assumed this role in the United States.
As the military has strong similarities to a dictatorship, some in the military are actively pursuing the goal of declaring a military dictatorship in the United States.