There's a reason it used to be called the Royal Pardon. It was the prerogative of kings.
Oh, what's that you say? It can be used to correct injustices? Yeah, that pendulum swings both ways.
Total amnesty for any and all crimes before the date of election and outlaw (hostis humani generis) for any and all crimes afterwards. It'll encourage people to be very afraid of accepting the job.
Hey, there are rules to split the loot honorably. This is totally unacceptable!