Which aspect of U. S. politics is most closely tied to the concept of direct democracy?

Democracy is due to the senator's and leader's elected from people's vote's like a president example let's say two people let's say me and you we want to be leader let's say your more of a trooper I'm more commander so they vote for me and I'm elected once elected i have power over many access to many weapon's enough to destroy the planet and can lead the world to good or bad due to power so leader's like them are the reason, So democracy is a tribe or "Team of authority's" with extreme power greater power the others. (Unrelated if i was elected i would lead the world to good not bad.)