Currently, Newt Gingrich owes small businesses 4.2 million dollars, that his campaign incurred from small businesses campaign stops. Gingrich's campaign induced those businessnes to provide goods and services during his 2012 failed campaign. Those small businesses provided varied services from lodging to aircraft, all provided services based on the good faith implied by Gingrich's campaign. Those small businesses had to unfairly absorb huge amounts of money, to the detriment of their business or their family's.
Candidates that aspire to higher office or any publicly held office should be ethically, morally, and personally responsible for any and all invoices due as a direct result of their campaign effort. A candidates refusal to pay invoices serves to point out further inequities.