The Star-Ledger of Newark said the source described Christie as influenced by conversations with Republican contributors dissatisfied with the current crop of candidates, and by some party stalwarts' attempts to convince him to run.
Christie may not have a lot of time to make up his mind. If he wants to run in the Florida primary, he would have to file by Oct. 31.
Christie gave a speech Tuesday at the Reagan Library in Simi Valley, Calif., and appeared Thursday in Baton Rouge, La., with Gov. Bobby Jindal.
He has been getting encouragement to run from former New Jersey Gov. Thomas Kean, a former star of the party's moderate wing, from former New York Gov. George Pataki and from Nancy Reagan. The New York Post said Thursday that Mrs. Reagan's encouragement moved Christie.
Barbara Bush is reported to have called Christie's wife, Mary Pat, several months ago to reassure her about life in the White House.
Christie ran for governor in 2009 after serving as U.S. attorney for New Jersey. His only previous elected office was as a Morris County freeholder.