>>But Australia is much smaller in population than USA.
it's per-capita, meaning the total $ amounts would be colossal in the US ... people regard a $1T deficit as a huge amount, but not so worrying if you have a scheme accumulating $200T in real assets. Compare to the current US social security scheme that is expected to run out of $ before 2037.
>> And (if my geography is correct) does not have a border with Mexico
LOL... but you could make all illegal immigrants citizens overnight and you'd be even better off: immigrant populations are younger, which increases the magic of compound returns from their contributions in a universal scheme, as opposed to surpluses being sucked away at the first opportunity.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
