Mr. Williams, those who know him say, can be quick to pick up a dinner check and has a driver ferry him around. In addition to the Chinese food deliveries, he sometimes has antipasto delivered to his door from an Italian restaurant in Mineola.

But he has few visible assets beyond his Cadillac, and this year alone, eight state tax liens were filed against his companies.

His biography, posted online, says he helped General Dynamics secure a $2.5 billion federal wire and cable service contract for minority-owned firms. Rob Doolittle, a General Dynamics spokesman, said he was unable to confirm that Mr. Williams played such a role.

One of nine children from the Lower East Side of Manhattan, Mr. Williams attended the State University at Buffalo on scholarship, where he played basketball and planned to pursue teaching, according to team rosters from the period. He graduated in 1971, and years later, he informed his alma mater that he had a law degree from Indiana University and asked that his mail be sent to Williams & Lockner, a Minneapolis law firm.

Officials at the Indiana University system say they have no record of the attendance of Mr. Williams. A founding partner of the Minneapolis firm, Thomas P. Lockner, doubted that Mr. Williams had any legitimate tie to the firm. In January, when Mr. Cox, the Republican Party chairman, named Mr. Williams to the advisory council, the announcement referred to him as the president of First Pro Group. State records, however, note that First Pro was dissolved in July 2010.

The companies he controls, most of them in his apartment, have names that indicate interest in a range of things, like trucking, electrical supplies and construction, and the contributions are often drawn from them. But there is little evidence that any of the firms have created jobs for anyone besides Mr. Williams and a woman, Barbara Brunson, who also lives in Suite 5L.