Zeroing in on a perception that Ms. Gillibrand too readily defers to Senate leaders, especially Senator Charles E. Schumer, he added: “We have a fundamental difference on independence. We have a difference on the level, the kind and the stature of advocacy New Yorkers deserve. And we have some honest differences on issues.”

He blasted her support for the proposed health care overhaul, which is expected to cost New York an extra $1 billion a year, and for opposing the taxpayer bailout of the financial industry.

“It was a mistake,” he said, noting that most Wall Street firms had already paid back the money. “How can you be against ensuring that the lifeblood of your city and of your state survives?”

Asked to grade her performance in the Senate, he said: “It would certainly be hard to give a grade that would be a glowing one.”

Mr. Ford, however, acknowledged that he gave Ms. Gillibrand a $1,000 campaign contribution shortly after her appointment, saying he had done so at the request of a friend. “She had only been a senator for two days,” he added.

After Mr. Ford, a five-term Tennessee congressman, arrived in New York, he took a job as a vice chairman at Merrill Lynch (now Bank of America). But he kept a toe in politics, becoming a commentator on Fox and then NBC, which features him several days a week on programs like MSNBC’s “Morning Joe.”

Speaking from a conference room at New York University, where he is a teacher, Mr. Ford, 39, expressed enthusiasm about his new hometown, though he described a life quite different than most New Yorkers. On many days, he is driven to an NBC television studio in a chauffeured car. He and his wife, Emily, a 29-year-old fashion executive, live a few blocks from the Lexington Avenue subway line in the Flatiron district. But Mr. Ford said he takes the subway only occasionally in the winter, to avoid the cold when he cannot hail a cab.