When a Democrat does something bad, a Republican with an interest in removing them from office must investigate them because that's the best way to ensure a thorough investigation.

When a Republican does something bad, a Republican with an interest in protecting institutions at all costs must investigate them because that's the best way to ensure a fair investigation.

I wish we had a Ken Starr instead of a Robert Mueller. I absolutely believe Mueller knew how his report was going to be used and summarized by Barr. If he didn't know that, he was too stupid to write it in the first place. He just didn't really mind all that much.