The fact that Ford pre-emptively pardoned Nixon is not an excuse for another president to pardon everyone under the sun that may or may not have committed a federal crime. I'm sure when Trump's term is over and he pre-emptively pardons a bunch of people, the Left will bitch about it just like the Right is today. I think it's an overreach of executive authority no matter who does it, but I don't think the practice can be outlawed. In this country we are all supposedly presumed innocent until proven guilty, and to deny somebody a pre-emptive pardon presumes guilt instead and that ain't a good road to go down. It's kinda reverse lawfare, to prevent somebody from retaliation even if they deserve to be challenged. As if politics wasn't already a very ugly and dirty business.