The only way to secure democracy is to only allow those who own land to vote. I'm not saying I think this is good or bad. I am saying it is the only way to secure democracy. Maybe there's a better alternative to democracy I don't know. Because we have yet to have that dialogue openly and freely. Current political tribes and cults have forbidden that opportunity.
And yes, this means those who own title and the rights to a plot within the borders of that nation.
There's no reason this could not be extended to the whole surface of the earth. Regardless of borders.