"You know, Romney spent $20 million in Florida in three weeks, and I think some of our guys decided to try to match him and we didn't have Wall Street (support)," Gingrich said. "I am going to spend some time paying it off. It is something I have done several times in my career."
None of the other Republican also-rans for president are as deeply in the red as Gingrich's campaign. Michele Bachmann's campaign has about $1 million in outstanding obligations, Rick Santorum owes $1.9 million and Rick Perry has only $14,463 to pay off.
Tim Pawlenty dropped out of the race owing $435,542 -- but Romney's campaign helped him raise money to retire the debt in return for Pawlenty's endorsement.
Campaign debts can haunt unsuccessful candidates for years, symbols of failure and futility they are unable to forget.
But losing candidates like Gingrich who hold no office face the biggest challenge in trying to retire their debts. The reason is simple: They are in no position to help donors or influence public policy.
Former New York City Mayor Rudy Giuliani still owes two dozen creditors $1.5 million from his unsuccessful 2008 run for President, while Hillary Clinton's campaign has $245,000 in unpaid bills.
Democrat John Edwards' 2004 presidential campaign still owes $333,500. The political committee of Republican Alan Keyes is saddled with a $301,000 debt from his failed 2000 run for president.
But in the history of campaign debts, Sen. John Glenn (D-Ohio) stands alone. He still owed banks, lawyers, a bumper-sticker maker, 161 former campaign workers and other creditors nearly $3 million more than 20 years after his failed run for president in 1984.
Glenn waved a white flag in 2005, notifying the Federal Election Commission that he was unable to pay them back. The following year the agency gave him permission to disband his campaign committee.