Presidents can't have even the appearance of wrongdoing. They have the welfare of the entire country as their responsibility. They cannot use their office to enrich themselves, their families of their friends. By submitting their tax returns their honesty and ethics or lack thereof will be available for all to see. Presidents who don't want to share their tax returns with their fellow citizens obviously have something to hide. And even if they don't they appear dishonest. C'mon Donnie, show us your tax returns. The President is not above any other citizen. He is the employee of the country. If we want to see his tax returns, he has to show them.