These were all good answers:
1. Encourage Hillary to stay in the Senate (no emails/Benghazi)
2. Call Fox News out for the cult it is and don't hold back.
3. Appoint Susan Collins to the cabinet
4. Don't appoint Napolitano to the cabinet.
5. Get someone else to run for the MA-Sen special
6. Encourage RGB and Breyer to retire ASAP.
I would add using every bit of political capital he has to have Congress ram through gerrymandering reform for Congressional districts and a new Voting Rights Act posthaste. This would probably be one of the most important things he could do.
