[mariodiana]

My understanding is that your characterization is true of the Articles of Confederation, but not true of the Constitution. The federal government's power is delegated from the people.

At the top of the Articles, it's pretty clear that the delegates of the states have come together to establish a league of states. At the top of the Constitution, it's explicitly stated that "We the People […] do ordain and establish."

[msgodel]

Individuals can't (practically) secede. And it is done via the states, for example the state governments choose senators. Right now this is done via popularity contests in every state but there's nothing in the constitution or federal law requiring that.

[vel0city]

> Individuals can't (practically) secede

Neither can states, either practically or legally.

https://en.wikipedia.org/wiki/Texas_v._White