Sorry to disappoint, but no Democrat will prosecute any Democrat POTUS for anything. Look at history for proof.
(Yes, I know you were not serious about that. ;^)
If any Democrat gets jail time under a non-Democrat administration, the Dems will be pardoned under the next Dem POTUS.
That's why it's crucial that traitors be punished with execution - as painful and public as possible to act as an example for future traitors.

And even Nixon was pardoned for his crimes by Ford.