it is not only two tiered. it is divided between the non-prosecuted Left and the overly prosecuted Right.
Yes, because the left is inherently corrupt so when they get power they use that power to protect their own, while the right tries to avoid that, even refraining from doing stuff like pardoning other people on the right that they know are innocent to keep from seeming partisan (remember Scooter Libby?).
Of course there are corrupt people on the right, but that’s an individual problem, it’s not inherent to their ideology.