// They've tried by hook or by crook for years to nail him with something. //
I wonder if this line of reasoning ever goes as far as reading into what the "something" is.
It's complicated law, for natural reasons the prosecutors will want the evidence to be damning and for the charges to stick (hence the length of time taken to bring many of these); and, since Presidents are at least functionally (and probably also actually) immune from criminal prosecution, then naturally there was a rather large four-year pause button on any of this.
Also many's the time Trump's been able to settle before things got as far as a criminal case when they arguably should have (eg his "Trump University" fraud).
Put simply, he's rich and powerful, and rich and powerful people are hard to nail even when the charges would otherwise been an open-and-shut case. The guy tried to rig the election in multiple ways.