u could ask them about the shortcomings of their economic/practical policy, e.g.
1. why is it that countries known to have a better quality of life (e.g. nordic countries, canada, etc.) tend to have more liberal/social democratic economic policies?
2. why do states that rank higher on prosperity, education, mental health care and other important metrics tend to be bluer while states that rank the lowest are often the reddest?
3. how can the usa compete with china's impressive infrastructure without equally committed investment in transit/cities?
4. why are murder rates on average higher in florida/texas than california/new york?
5. given that the last two republican presidents cut taxes without offsetting spending cuts, is that approach sustainable and how would it work with today's interest rates?
(stole the last two from twitter)