A one-hitter who repeats the same tired mantra over and over. It's used to described some shrill, tired ideologue or academic that pompously echoes some quaint notion or idea endlessly, and expects everyone to see his supposed wisdom and bow in concurrence.
Bruce is Johnny One-Note. He thinks the solution to the nation's debt crisis is the government continually spending more and more. Following his counsel will only worsen the predicament.