While discussing the Constitutional obligations of the Federal Government in another thread, I read this: The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States. Impost is another word for tax. So how can some Americans be expected to pay a higher percentage of income tax than others?