Not being a US citizen* means I cannot vote in US elections, thus it is a closed door vote by your reckoning and so the US is not democratic. Did I get that right?
*This is shorthand for me not being associated with the US in any way, but you are of course free to reply with all the edge cases that makes the point impossible to state briefly.
It does become a problem when the US claims global jurisdiction for its laws or tries to impose laws on other people.