Your commentary is confusing, The point Mr. Sowell is making, is that the only way to prevent career politicians to perpetually seek office is to term limit them out of their jobs. Not just their current jobs, but to limit them from just running from one political job to another. Perhaps a rest period could be initiated where a politician must take a break of at least one election cycle before becoming eligible to run for a different position.
I believe that would be more in honoring the intentions of the founders. There is no way to eliminate the promises made by candidates, but term limits would prevent office holders from using their office to favor certain campaign contributors.