Just googling I found floating rate notes, which seem to respond like an adjustable mortgage would. But they seem small and short term.

But I do understand we have a deficit and have to sell more treasuries every year.

Maybe that would be a driver to have a more even budget.

But from my perspective Dems pass policy that a large % of the country likes. Raise taxes to pay for it. Republicans then win election and repeal and cut taxes but leave said popular policy. next Dem majority raises taxes but probably not even above the baseline before Rs cut it (e.g. the current draft reconciliation bill doesn't actually raise taxes much at all. it's crazy to me how cheap some of this stuff is when you take legit CBO scored credit for instance not handing out billions to pharma)