Trump didn't address the debt, maybe the only promise he didn't keep. Then again, he doesn't write spending bills, and he can't pass a budget using executive orders. The last budget that wasn't a deficit was authored by Newt Gingrich, opposed by the democrats who actually shut the government down during negotiations, but eventually signed by Bill Clinton.
I saw a statement that Trump inherited a strong economy, that's laughable. Eight years of suck presided over the longest extended period of economic malaise since the great depression. Not so much as one good year out of eight. Trump turned the economy around by simply undoing Obama. Leading to an increase in jobs, an increase in manufacturing jobs Obama / Biden told us ARE NOT COMING BACK. Maybe most importantly, an increase in real wages, something we haven't seen in decades.
If people thought Obama / Biden did such a great job, democrats don't lose > 1,000 seats at the federal and state legislatures. They lost the Senate (started with a super majority), they lost the House, they lost the White House and they lost control of the States as a whole. Those are epic losses.
If it wasn't for the pandemic, we're looking at something that may have rivaled 84 or 88, but now we're looking at a year 2000
Only one thing can reduce our deficit, spending cuts. Let me know when a career politician campaigns on this that's not named Paul
As for the party most responsible? That's really easy, just look at the state deficits / debt. The worst debt in the country is dominated by blue states, it's not even competitive. And the most telling part of those blue states deficits? they're all high tax states, go figure.