Repeating a bit, but we already do this between states in the US and in the EU, so clearly it can work in practice.

Because voters decided there was a common interest, cultural identity, etc. and mutually agreed on political integration. Voters clearly do not want a unified Americas.

The purpose of a Republic is to be a stable entity that ensures the welfare of its citizens. It is not to have a single-minded obsession with global welfare at the expense of its own sustainability or the desires of its citizens.

> voters decided there was a common interest, cultural identity, etc. and mutually agreed on political integration.

I'm less confident that this was performed in either location due to direct democracy, and more because it made political sense and was expedient at the time that these locale enacted the governance structure.

In other words, it's not a one-and-done-forever type discussion, and things (clearly) evolve over time.

We don't elect an all powerful leader. The people did vote for Trump. But "well they voted for Trump" is not an excuse for him to do literally anything. If the people want legislative changed then they elect people in Congress. If the people want to change the constitution itself then they can seek that too.

But "well Trump won so just have ICE kill them all" (this is what my aunt, a republican lobbyist, wants) is not a thing.