"To lay taxes to provide for the general welfare of the United States, that is to say, 'to lay taxes for the purpose of providing for the general welfare.' For the laying of taxes is the power, and the general welfare the purpose for which the power is to be exercised. They are not to lay taxes ad libitum for any purpose they please; but only to pay the debts or provide for the welfare of the Union." - Thomas Jefferson (1791)