Considering that Rome only truly ended it's existence in the form of the Byzantine Empire during the Middle Ages, i would first say that America is right now most likely entering a transitional stage between one form of governance and another.
When a group of people begin to look at a political system as something which is inherently "American", they fail to see that a political system is something which is subservient to the ideals of the people - in otherwords the political system becomes something which negotiates with the populace from a greater position of strength.
Patriotism is what gave the administration their power, and the Administration saw to it that Government was seen as a patriotic ideal.
