During the past five years, Gingrich has raised about $52 million, of which some $621,500 is expendable cash on hand. Donors include Las Vegas Sands CEO Sheldon Adelson, NASCAR vice president James France, and corporate donors in the energy industry. Due to FEC restrictions, Gingrich does not have full control over how the funds are spent.

AP Photo/Cheryl Senter
Former Speaker of the House Newt Gingrich speaks with Secretary of the N.H. GOP Greg Carson of Londonderry at the kick-off event for the The New Hampshire Republican State Committee's 'Live Free or Die' Speaker Series in Manchester, N.H. on April 20.