As a matter of fact, it is ;) A system where everyone can personally choose their leaders without external pressure or control is called a democracy.

This is really strange attribute of democracy, that if majority decides (informed or by uninformed that decision be), one can flip from democracy to (let's say) autocracy, but then you dont get to vote in next election if you change your mind, because there will be none.

The original intent of the 2nd amendment (right to bear arms) was to void a scenario like this, by giving enough military power to the people to make impossible for an elected government to switch to autocracy / dictatorship / ... without the approval of the population.

Wether this amendment is still needed, and if it's effective considering the evolution of military technology, is open to discussion, but at least the original constitution tried to avoid this.