I don't know about McGahn's history, but Mueller has a spotless (I think) history of just doing his damn job.
Yeah, no. He does not. He has a history of having everything he ever did torn to shreds by the Supreme Court. See: Whitey Bulger, Ted Stevens, and Arthur Andersen. The better equivalent of Bob Mueller is Mike Nifong, infamous over-zealous prosecutor in the Duke Lacrosse case who was ultimately proved to be a political hack out to throw people in jail no matter what solely for political purposes.
Mueller is a sham artist, and a shameless one at that. That he couldn't find anything to manufacture in this case winds up being a testament to Trump's being careful not to fall for a trap more than anything else.
Mueller is a scumbag. I've met his type before in prosecutions. They will never give up their cause until they themselves are personally arrested and jailed for their misdeeds as prosecutors (as is what happened in my case; I took particular joy in watching that Napoleonic little bastard get hauled away in cuffs after he falsely imprisoned dozens of people by simply intimidating them into guilty pleas).
Mueller himself should be investigated with a freaking microscope and the
instant that anyone finds anything amiss, he should be cuffed, stuffed, and held without bail as a flight risk. He has tremendous assets and connections to get him out of the country to avoid prosecution and he should be treated as such: an irredeemable flight risk who cannot be trusted to return to court to face the music. Give Mueller the same treatment that he gave others: bust down his door at 5:00 in the morning with a SWAT team and a no-knock warrant and throw his wife and kids (if he has any) out into the front yard in their pajamas just like he did to others, making them stand there shivering for hours while the CNN cameras are rolling live. We'll see how much he likes it then, and then the Democrats will finally learn to worry about their own corruption and scurry like the cockroaches that they are from the light that just came on in the kitchen.