Require candidates for POTUS to have at least one year of public service, take and pass a basic civics exam, and publish ten years of tax returns.
Why is this important?
Stringent job qualifications are required for most high-level positions in the government and in the private sector, but this is not so for the most critical position of all, the President of the US. The candidate for this office should at least be able to pass a basic civics exam, should know from experience what public service entails, and can prove to the voting public that he or she will not carry business conflicts of interest into the Oval Office.