Do you honestly believe that in the US the Congress rules the country?
Do you honestly believe that the President has less power than the Congress?
Do you honestly believe that the President and the congressmen are independent and take important decisions?
Do you believe in life after love?
The US are ruled by the 12.
Congress does actually run things. Why do you think Trump appointed Muller as a Special Prosecutor just to investigate himself? The Senate got cold feet and demanded it or else they would investigate him themselves, which would have been very messy.
It is called checks and balances, the president and congress have different forms of power that checks and balances each other so that no power becomes dictatorial.
America is ruled over by various oligarchs, plutocrats, and bourgeois, along with the military industrial complex, along with various intelligence agencies. They are changing with time and fighting each other.