I'd suggest looking at two things. What percentage of the economy tax receipts represent and the breakdown of how much revenue comes from the top tax brackets. You could also look at spending a percentage of GDP over time.

My view with all that in mind is that spending has gone up quite a bit. Overall tax revenue has stayed remarkably consistent and the tax system is progressive (i.e. if you make more you pay more). Is it progressive enough? I don't know. What percent of the budget should that top 10% (or top 1%) be paying? 20%? 30%?

At the end of the day though getting 20% of GDP in to the Federal government as tax has historically been a heavy lift. If you get a government that's willing to vote to do that then I would be that that you will soon find new one that's willing to vote not to do that.

That said getting spending in the range has the same problem.

At some point though it seems inevitable that one (or both?) of those statements will prove to be untrue.