He may be a reluctant white hat to save his ass?
Maybe. I'm thinking he has no need to investigate, let alone prosecute any DEM. He can apply the double standard to his charter by advancing charges on anything that points to any person in or related to the Trump campaign and looking past all other crimes as being outside of his scope.
Acting like that protects his standing in his social circles and doesn't expose him to any legal jeopardy.
Podesta wouldn't be totally off the hook, he'd just not be on Mueller's.