> A century more?

No one knows because it depends on a lot of variables that cannot be predicted in advance. The only major short term threat is that we default due purely debt ceiling debates / brinkmanship, not because of the burden of the debt itself.

The debt becomes a very real problem if hegemony of the US dollar as a reserve currency is ever disrupted. I don’t see that happening anytime soon, though.

> What's the future of the state as an institution?

Very high tax rates, unfortunately. Although there’s worse outcomes (currency destruction). These are the possible long term consequences.