Tyler Cowen has some fun proposals:
1. Allow all candidates to watch a short debate of experts -- with a fraud or two thrown in -- and ask them to evaluate what they just heard and why they reached the conclusion they did.
2. Test candidates for the ability to spot liars.
3. Give each candidate a substantive message and then give each two minutes to turn it into pure fluff. This tests communications skills, plus we can see the meat grinder in action.
4. Require each candidate to conduct an orchestra. Watch to what extent each candidate defers to the players, and to what extent he prefers "panache."
Or ask them, if all else fails, what they'd actually do in Iraq if they were president right now. There's a concept.