Thomas Jefferson says...

"They are not to do anything they please to provide for the general welfare...To consider the latter phrase...as giving a distinct and independent power to do any act they please which may be good for the Union, would render all the preceding and subsequent enumerations of power completely useless. It would reduce the whole instrument to a single phrase, that of instituting a Congress with power to do whatever would be for the good of the United States; and as they would be the sole judges of the good or evil, it would be also a power to do whatever evil they please...Certainly no such universal power was meant to be given them. It was intended to lace them up straightly within the enumerated powers and those without which, as means, these powers could not be carried into effect." ––Thomas Jefferson, Opinion on National Bank, 1791