While Barack Obama and Mitt Romney raise millions of dollars daily, presidential also-rans Rick Santorum and Newt Gingrich remain saddled with debt.

Gingrich’s situation is most dire: his campaign is than $4.7 million in debt with less than $736,000 cash on hand through May, new federal campaign filings show.

That Gingrich raised almost $500,000 dollars in May — he even scored $700 from the sale of a used laptop computer — wasn’t nearly enough to offset money owed to about 120 different creditors.

Some debts are massive, such as the more than $1 million owed to air charter company Moby Dick Airways and the more than $466,000 to Virginia-based Patriot Group for security services. The campaign also owes Gingrich himself more than $580,000 for travel expenses.

Others are more pedestrian: Alberto Acereda of Arizona is due $3,500 for “Hispanic outreach” services, while Illinois-based photographer Matthew Georgopulos is waiting for a $350 payment to materialize.

Gingrich’s debt through May is effectively unchanged from the end of April, federal records show.

For Santorum, his campaign owes more than 30 creditors a combined $1.94 million through May, his latest filing shows.

Among them: Consulting firm Brabender Cox ($727,987), advertising company Emotive LLC ($528,348) and database management service CMDI ($117,927).

Santorum’s committee did report nearly $700,000 cash on hand, having raised more than $454,000 last month from thousands of donors, many of whom contributed small amounts.

Its financial situation hasn’t materially improved since the end of April, however, when it reported more debt — nearly $2.3 million — but also more available cash, at $1 million.

One GOP candidate with no such troubles?

Ron Paul, who ended May with nearly $3.3 million in the bank and no debt.

It’s not uncommon for a presidential campaign committee to carry significant debt for months, even years after a candidate’s bid went bust. Notable examples include Bill Clinton, Hillary Clinton, Rudy Giuliani, John Edwards, Pat Buchanan, Dennis Kucinich and Al Sharpton, according to the latest federal records.