Ignoring all other considerations, the current incumbent political party in the US presidency on average tends to produce effective & functioning federal agencies, and the other party on average tends to produce corrupt & dysfunctional federal agencies.
I try to point this out frequently because voters tend to ignore this kind of thing until it affects them personally, or they read about some isolated grievance in the news. But it really should be considered a more important topic.
voters tend to ignore this kind of thing until it affects them personally
And when it finally becomes a problem that cannot be ignored, scapegoats will be found and used, even if they have to be invented in a fairy tale (internet conspiracy).the federal agencies are mostly employees have been there through many administrations. How do they suddenly become corrupt and dysfunctional besides these employees (90% of the current incumbent political party) suddenly becoming corrupt and dysfunctional?
That means leadership can change the course of an organization by ruthlessly making them do other things until people internalize those things as the right thing, or leave.
That only explains decay though, not the magical idea that under the right party things spring back. The best to hope for is a democratic president to slow down the decay. But it is simply so much easier to tear things down than to build things up, that it will take a lot of democrats to see actual improvement.
However, they've learned. At the end of his term, Trump created a new classification of employment, Schedule F. Schedule F employees did not have civil-service protections and could be fired on a whim. Fortunately, he lost the election before he could use it. Biden removed it.
Now, Trump-aligned groups like the Heritage Foundation are running programs to recruit Trump loyalists whose main and almost sole qualifications is loyalty to Trump (see Project 2025). They don't want a repition of last time where federal employees had the gall to actually follow the law instead of the dictator.