The very first power given to Congress by the Constitution is the power to tax. Money is power, and in the governmental structure created by the Constitution, Congress—not the president—controls the money. Congress also has the power to levy tariffs (taxes on imported goods) but it's not allowed to charge more for imports into one state than into another. The Framers of the Constitution probably put the tax power first on the list of Congress's enumerated powers because they were acutely aware that one of the biggest problems of the old Articles of Confederation was that its version of Congress did not have the power to tax, and thus didn't have the power to do much of anything at all.