As he continued his long-shot run for the Republican nomination for president during the month of April, Newt Gingrich incurred more than $1.3 million in debt, according to a review of his most recent campaign filing report.

Part of the money was paid back during that same month. But the list of vendors still waiting to be paid range from big companies to mom-and-pop shops, from well-established political organizations to small-town consultants. In total, the former House Speaker ended April with $4.7 million in debt.

To be sure, it was a risky move for these businesses and individuals to willingly incur debt from a campaign that was already already operating in the red and had no visible means of survival. Yet while many of these vendors can survive years without repayment and still avoid default, others are currently in limbo, wondering whether their business will survive the financial hit. With Gingrich having formally suspended his campaign on May 2, the question has become: who will he pay back first?

In April, the Akron, Ohio firm InfoCision took on more than $180,000 of debt for telemarketing work it did for the Gingrich campaign. The firm received payments totaling $110,615 during that same period. But due to an outstanding balance for work done prior to April, InfoCision ended the month being owed $138,293. A call to the firm was not immediately returned.

Next to Gingrich himself, InfoCision took on the most campaign debt during the campaign's final month. But others weren't too far behind. Campaign Fundraising Experts LLC of Mesa, Ariz., incurred more than $170,000 in debt for web ads in April, in addition to the $36,266 it was owed heading into the month. It received payments totaling $41,755 in April, meaning it was still owed $165,000 at the end of the month.

Gingrich leaned on his campaign surrogates to take an upfront hit. Herman Cain Solutions, the failed candidate's post-campaign political enterprise, took on $16,525 in debt from the Gingrich campaign during April, for strategic consulting and travelling expenses. A group run by former Rep. J.C. Watts (R-Okla.), J.C. Watts Enterprises, was owed $35,000 at the start of the month. Neither group received payments in April.

Some companies can take the hit. The Gingrich campaign has not yet paid tech giant Twitter the $12,763 it owes from a media buy. But others are likely struggling a bit more. Peace River Company, in Studio City, Calif., incurred $22,000 in debt for photography services during April; Oak Grove Communications in Decatur, Ga., incurred $2,400 in costs for communications consulting; and R Squared Associates in Pleasanton, Calif., incurred just over $1,400 for printing and postage services.

As Gingrich lacked a truly plausible shot of winning the nomination during his final weeks as a candidate, his campaign could have, conceivably, used donor money to balance the books. Instead, the former House Speaker spent with alacrity and on items that seemed either duplicative or unnecessary. He raised just under $790,000 in April while spending $1.2 million.

In April, Gingrich spent $5,000 on polling, $10,000 on ballot access consulting, $171,765 on salary (with $24,890 in payroll taxes) and $39,014 on "strategic consulting." Even though Gingrich had Secret Service protection, he still spent $32,113 on "security services." Despite having failed to qualify for the Virginia primary, the candidate still paid the Virginia Secretary of State $50 in filing fees. And while he made criticism of President Barack Obama's use of a teleprompter a key laugh line in various campaign speeches, he paid Greenberg Teleprompting $650 in April.

Some payments were more cryptic than others. At the beginning of April, the group Michera LLC was owed $12,000. It incurred $6,398 in additional debt during the month, but had been paid off in full by the time it ended. The Gingrich campaign paid the limited liability corporation for "transportation services," according to the filing report. But there is virtually no history of the company on the web, let alone an indication of what it does. Virginia state records lists Crystal Urrutia as its registrant. Several calls to Urrutia went unreturned. R.C. Hammond, a spokesman for Gingrich, told The Huffington Post: "The vendor is not a private plane broker."

The Gingrich campaign lists MNL LLC, a vendor it owes $9,500, as occupying the same address as Michera LLC. Virginia records, however, place MNL LLC in an entirely different town. The registrant listed for that limited liability corporation is named Matthew N. Latimer, which is also the name of a George W. Bush administration official who wrote a critical book about the former president. Latimer did not return a request for comment.

Why Michera LLC's debts were paid and MNL LLC's were not is unclear. There are 104 vendors whose bills have yet to be fully paid off by the campaign, for amounts ranging from $327 to $1,032,072.

Some campaign vendors are finally seeing checks come through. Angel de la Portilla, a political consultant in Orlando, Fla., told HuffPost in April that the campaign owed him $6,000 for voter outreach services (federal records listed the debt at $3,840). "It's just disappointing they way it's being handled," he said at the time. On Monday, Portilla said he'd been paid the full amount.

But Larry Scheffler, president of a Nevada printing company that made campaign signs for Newt 2012, said he hasn't been paid the nearly $8,000 he is owed, despite assurances from Gingrich himself that the money is on its way.

"Still waiting until the cows come home," Scheffler said in an email.

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