As a technically “first offender” they can argue that it shows obvious bias and get a favourable appeal result.
It plays to Putin and other autocrat propaganda. “See how the US actually is, we have the same democracy here” sort of thing.
Most importantly, it plays to his cult and to his ego, he gets to stoke dangerous things which very nearly almost worked last time (only thanks to Pence and the few cops who stood up to the mob.) and he gets a ton of attention from his cult for it.
You’re looking at it from the wrong angle.
He wants a tough sentence with jail time.
I think he’ll think that until the cold wet fish of reality slaps him in the face.