From the Boston Tea Party through recent revelations of Internal Revenue Service abuses, paying taxes has aroused public passions in the United States. Every president in the past four decades has proposed significant tax changes, and successive Congresses have enacted many tax bills, major and minor. Seemingly endless tinkering has not, alas, bred satisfaction. Almost everyone concurs that the tax system could be improved. But agreement on the nature and severity of the problems and how to resolve them remains elusive.