I consider the foundation of the Constitution as laid on this ground: That "all powers not delegated to the United States, by the Constitution, nor prohibited by it to the States, are reserved to the States or to the people."In short, Jefferson regarded the now sadly neglected 10th Amendment as a bedrock principle of the new republican government, and a vital bulwark to keep it strictly limited. High time to make up for that neglect.
To take a single step beyond the boundaries thus specially drawn around the powers of Congress, is to take possession of a boundless field of power, no longer susceptible of any definition.
Certainly no such universal power was meant to be given them. It was intended to lace them up straitly within the enumerated powers.
Opinion on Creating a National Bank, 1791
[For extensive commentary on the 10th, see Dr. Randy Barnett's fine book, Restoring the Lost Constitution.]
[Hat tip: Robert Tracinski, TIA Daily, July 4, courtesy of Ted Keer.]