How would one go about getting this added to the Constitution? Asking for a nation.
@yurnidiot What about other nations? Can they have billionaires ?
@DavidBHimself Sure, but our schools, health care and other public amenities would make it quite attractive for them to live here as millionaires.
@phoefer "our schools"?

My reply to OP is mostly to underline how they consider their country as the only one that matters, and I guess you're going on step beyond, assuming your country really is the one one that matters to the point you assume we're all from that country. Or am I misunderstanding?
@DavidBHimself You're right, I was assuming this to be a hypothetical scenario where we're all in the same country (I know we're not) because I find that to be the best context for discussing policy changes. It's how I understood the original post.
I understood your post as pointing out that billionaires would just move to a different country and I wanted to make a case that there are arguments against that.