Even if savers never demand a little extra interest because of concern about Uncle Sam's creditworthiness, keeping debt service from overwhelming every other part of federal spending might require a maneuver called financial repression. That means shortchanging savers by paying them less interest than inflationa negative real interest rate. It has been done in the pastfor example, in the years following World War II when bond yields were kept artificially low to pay down huge debts racked up to defeat fascism. And there have been periods of negative real rates following the financial crisis too. The more recent episode wasn't done to bail out a profligate government, but that doesn't mean it can't serve that purpose in the future