The Republican presidential candidates raised and spent money at a frenetic pace last month, according to new financial disclosures.
Reports filed with the Federal Election Commission this week suggest Mitt Romney's campaign spent $19m (£12m) in January, nearly three times as much as it raised, while Restore Our Future, the so-called "super PAC" or political action committee backing his campaign, raised $6.6m and spent $13.5m. Donors to Mr Romney's PAC included the Marriott chairman JW Marriott and the Hewlett-Packard CEO Meg Whitman.
The campaigns of Newt Gingrich and Rick Santorum raised $5.6m and $4.5m, respectively. But in Mr Gingrich's case, his PAC, called Winning Our Future, raised $10m in donations.
In contrast, the Super PAC that backs President Barack Obama, Priorities USA Action, reported raising only $59,000, with $50,000 coming from one donor.