That explains a large part of why democrats were able to lower the debt - the republicans in congress wouldn't go along with efforts to raise the debt.
Cutting taxes without cutting spending raises the deficit and seems to be the GOP's most common fiscal policy.
They increase the deficit because they increase spending and then "cut" taxes. Often they don't effectively "cut" taxes for you and me: the tax burden for many Americans is raised, except for a select few who get tax cuts.
This was happening well before Trump, into Reagan. The only reason this works at all is because they get to say "oh we cut taxes!". But tax burden is very complicated, and nobody is analyzing that for the common voter.
Complete nonsense in practice, obviously - but political gold! Voters get all the same public services, lower taxes, and to think they're being responsible with money. And if you're a 65-year-old legislator, you'll be dead and buried before the consequences start to bite.
The best way to make sense of the GOP is in it's opposition to wealth redistribution. Primarily downward wealth redistribution. That's their north star.
Upward redistribution is mostly OK though, they consider it just giving rich people their own money back