Is the USA a republic or democracy?

      

      
     It is both. They are not mutually exclusive. A republic is a form of government, and a democracy is “an element of who elects the empowered,” they are different domains. It is perfectly possible to have an undemocratic republic, and it also possible, strange as it sounds, to have a democratic monarchy. 
Republic describes the structure = as opposed to anarchy, monarchy, oligarchy.  Democracy describes how those leaders are chosen.  USA is a democracy in that the legislature & executive of the republic are determined by democratic popular vote. Indeed, in a last resort in USA democracy does trump constitution.
That is why there is a process for constitutional amendments.  As such, it is a democracy where majority rules - one could have an electoral process that rewrote the Constitution. They would be a very high bar (rightly) and slow, but it could be done.

     
 

     When the U.S. was formed, the key differentiation from a governmental perspective was that it was a democracy in comparison to England which was at the time a monarchy.  As always with word choice it depends on what you want to emphasize. If you want to emphasize that a government is controlled by its people, democracy is probably your best word choice as its that's what the word implies. If you want to emphasize that a government is limited in power by a constitution, then a constitutional republic may be a better choice.  In referring to the U.S., and in comparing it to other forms of government, highlighting that the people have such a large role in determining the government seems desirable, more so than other things you might highlight like the constitutional limits on power. That's the likely reason why democracy is more often used to describe the style of government the U.S. employs.




 

     
      It is a distinction without a difference in a country where half the people don't vote and the other half go through the motions believing that the whole thing is a screwed-up mess run by backgound sociopaths pulling strings with money anyway.  There are only two political systems in the world: ones where the people feel represented enough and prosperous enough to not stage violent coups every generation, and ones where they don't.  All the countries in the first category, in all their glorious variety as far as political systems go, suffer basically the same pathologies. Hence: distinction without a difference.


      

 
     A great mixture of ideological currents (English 17th century  constitutionalism, 18th century Whiggish thought, Lockean political theory, Scottish common sense realism, Renaissance republican theory, Enlightenment political liberalism, French rationalist separation of powers theory, and the examples of ancient Athenian and Roman republican governance)  came together and produced and animated in contention with each other both the American Revolution and subsequently the US Constitution.  Most people haven't read John Adams' Thoughts on Government or the Federalist essays of Alexander Hamilton and James Madison, or Madison's notes on the constitutional convention.   Most people are unaware of the ideological nature of the colonial opposition to Britain in the 1760s, or the nature of how American colonial governance had evolved over the 18th century into a practical ad hoc dress rehearsal for separated powers representative republicanism, or aren't familiar with the idea that Athenian style democracy was feared as mob rule or anarchy during that era.  


 

     The USA is  this way because that's the way the Founders wanted it. They did not find the idea of a (pure) democracy attractive and wanted to put a contemplative body -- Congress -- between the masses and power. But they did not trust that body to be free of emotional influence, either, and established a system of checks and balances among three seats of power: the President, the Congress, and the Court.  Thomas Jefferson said it best in the Declaration of Independence:

...to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, --That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it... [Emphasis added]

John Adams referred to the ancient concept of "tyranny of the majority" back in the eighteenth century, when our republic was still finding its legs. There was a fear (and it was an old fear) that a pure democracy could in fact lead to tyranny, as a democratic majority could easily overwhelm, even harm, a minority. Benjamin Franklin was asked what type of government we had when the country was forged and he replied, “A republic, if you can keep it.”  

     In the strictest sense of the word, the system of government established by the Constitution was never intended to be a "democracy." This is evident not only in the wording of the Pledge of Allegiance but in the Constitution itself which declares that "The United States shall guarantee to every State in this Union a Republican Form of Government" (Article IV, Section 4). Moreover, the scheme of representation and the various mechanisms for selecting representatives established by the Constitution were clearly intended to produce a republic, not a democracy.
To the extent that the United States of America has moved away from its republican roots and become more "democratic," it has strayed from the intentions of the Constitution's authors. Whether or not the trend toward more direct democracy would be smiled upon by the Framers depends on the answer to another question. Are the American people today sufficiently better informed and otherwise equipped to be wise and prudent democratic citizens than were American citizens in the late 1700s? By all accounts, the answer to this second question is an emphatic "no."


Our constitution, especially with the individual liberty and states' rights guarantees in the Bill of Rights, was meant to stop such a thing from happening.



It may not be perfect, but I'd rather have a republic, even with our easily corruptible legislators, than a full-on direct democracy any day.