It looks like it was under control for a while following World War II, but then from the early 1980s, it's hard for me not correlate the first derivative of the slope of that graph with presidential party.
Democrats had a near solid lock on Congress from World War II until the early 1980s (only 2 two year sessions where they didn't control both chambers) and Congress hadn't abdicated its power of the purse.
Republicans spend a lot of time branding themselves as the "party of fiscal responsibility", but ask yourself in what situations a group needs heavy branding by way of incessant self messaging. By every major objective measure, Republican control of government has been worse for the economy.
And to be clear, none of this reply is meant as a defense of the current Democratic party which is currently (at the national level) leaderless and in shambles and is far too captured by its donor class of special interests to protect the interests of the American working and middle classes and who will be unable to regain real power until they address that.
Many years ago I recall seeing a chart that annotated-out the party had the Presidency or majorities in either house of Congress along the "time" axis, but I'm not having any luck finding one. Sort of like this [0] except including a line for deficit/surplus by GDP. [1]
There are a lot of charts out there where the Presidency is shown, but IMO that plays in to a false narrative about who really has power over budgeting and how-much.
[0] https://www.pewresearch.org/short-reads/2021/02/03/single-pa...
It was held together by decorum. There is none left.
It seems to be a pattern, where a disturbingly-large minority of people remember nothing but the year-number of an election (e.g. "2008") and never account for how voting was at the end of that year and the voting-result only takes effect the next (odd-numbered) year.
Oh, there's also a general "I want it to be true so I remember it that way" aspect, but I think that's contributory rather than the main cause.
1942-1945: Big increase to pay for fighting/winning a World War
1946-2007: More or less fiscally responsible
2008-present: War-like level of debt increase to counteract a down business cycle?
I recommend the surplus/deficit by GDP graph, which is easier than manually eyeballing slopes: https://fred.stlouisfed.org/series/FYFSGDA188S