I'll make a relatively simple observation, though. The Republican position, predictably, is that Strzok didn't like Trump, and Strzok was initially a part of Mueller's investigation, therefore the entire Mueller investigation is tainted, and Trump must be declared completely innocent.
Shall we apply this to Clinton, Bill or Hillary? Or any Democratic politician? I could go back to Ken Starr, but I'm really more interested in Comey's clear distaste for Hillary Clinton, as evidenced by his public excoriation of her when he announced that he wouldn't prosecute her. Recall that this was part of the original, and clearly bullshit justification for firing him in the Rosenstein memo-- his overly harsh treatment of Clinton, which was clearly personal. One agent who chose to remain anonymous called the FBI "Trumpland" during the 2016 election, amid leak after leak from the FBI aimed at hurting Clinton. FBI agents, including Strzok, hated Clinton. (Of course, the GOP doesn't want to talk about what Strzok thought of Clinton...)
Does this invalidate any FBI investigation of Clinton and vindicate her? To apply congressional Republicans' current argument, it would have to. If Strzok's hatred of Trump vindicates Trump, then the FBI's hatred of Clinton must vindicate Clinton.
Of course, the GOP is calling for more and more investigations of the woman who hasn't held any formal office since 2012. Why? Because this isn't about facts or reason.
There is a trope in police procedurals where a corrupt cop has all of the people he ever arrested set free as soon as internal affairs finds out that he took a bribe (which isn't even remotely close to what Strzok did). Investigations are supposed to be decided on the facts. The facts, for the GOP, are pretty bad. Lots of contacts with Russia, lots of attempts at coordination, lots of lying, Trump firing the FBI Director to shut down an investigation, and I won't even bother trying to summarize everything because there is simply too much. If this is decided on the facts, the GOP loses. However, this will instead be decided by... the GOP. Mueller can indict anyone lower than the president for federal crimes, and Trump can pardon them. As for Trump himself, as I keep telling you, he'll never submit to an interview, and no matter what, congressional Republicans will never impeach. Their excuse will be... Strzok! Deep state! Aliens did it! HILLARY'S EMAILS!!!!!!! Is it bullshit? Yes, but that doesn't matter to them. Fox will lap it up like the lapdogs they are (I love English!), Republican voters are blind here, independent voters will be overwhelmed by inconsistent messages from Democrats and Republicans, and chalk everything up to partisan bickering. Trump gets away with it. If the economy chugs along, he wins in 2020.
In other words, this is a bad faith argument, and obviously so when you consider the attitudes at the FBI towards Hillary Clinton, combined with Republicans' never-ending obsession with her.
Eventually, Hillary Clinton will die. She's not a vampire. (Sorry, Jason Isbell.) Anyone want to bet that the GOP will start a "Hillary faked her own death to escape the email investigation!" conspiracy theory? I'm not joking about this. I wish I were. Would it be less crazy than pizzagate? Would it be less crazy than any of the shit that Donald Trump says on a daily basis? Dude listens to Alex Jones.
Yeah, as far as the GOP is concerned, Peter Strzok's dislike of Trump means Trump must be innocent, but let's still go after Hillary and ignore what happens if we apply that reasoning to the Rosenstein memo.