We may not like – even as we come to understand – what (apparently, illegitimately appointed) Special Counsel, Robert Hur, said about Biden’s potential ‘appearance of competency’ in a trial, but it’s worth noting what else Hur said in his Report:
“It is not our role to assess the criminal charges pending against Mr. Trump, but several material distinctions between Mr. Trump’s case and Mr. Biden’s are clear. Unlike the evidence involving Mr. Biden, the allegations set forth in the indictment of Mr. Trump, proven, would clearly establish not only Mr. Trump’s willfulness but also serious aggravating facts.”
"Most notably, after being given multiple chances to return classified documents avoid prosecution, Mr. Trump allegedly did the opposite According to the indictment, he not only refused to return documents for months, but he also obstructed justice by enlisting others to destroy evidence and then to lie about it. In contrast, Mr. Biden alerted authorities, turned in classified documents to the National Archives and the Department of Justice in 2022 and 2023, consented to the search of multiple locations including his homes, permitted the seizure and review of handwritten notebooks he believed to be his personal property, and in numerous other ways cooperated with the investigation."
It’s the kind of nuance that’ll never land with the actual red-hats, but – as I often say – they aren’t the audience.  Legitimately persuadable ‘undecideds’ are.
Also worth reminding that cohort …
One of the things about all of these conspiracy theories (eg, “Deep State,” corrupt DOJ/FBI) is how intricate and complex they are, and how many people would have to play difficult roles extremely well.
Ridiculously unlikely.
Occam’s Razor says, in effect, that “the simplest of competing theories [should] be preferred to the more complex …”
The simplest answer is that Trump is a criminal.  That requires FAR less mental gymnastics, ignorance of facts, internal contradictions, and hypocrisy than any other theory.
The same audience can likely get their minds around that.