The more I think of it, it actually makes sense to simply execute all presidents, after they've served their terms. That would leave them with no incentive to stuff their pockets or otherwise benefit from it, other than to serve society. After you've done, you're gone, that's the deal!
The only ones who would be willing to run would be the likes of Mike Gravel and Bernie Sanders, experienced, unselfish idealists at the end of their life willing to do one final thing to improve society. Maybe they got things right in Haiti after all…. it's almost scary how much sense it makes!