Kudlow pressed further, asking whether the individual mandate was "your biggest mistake."
"One thing I learned--one thing I learned is this, which is that you don't take ideas from a state and try and impose them on the whole nation," said Romney. "Our nation is too different, too diverse to say that what works in Massachusetts is somehow going to be grabbed by the federal government, usurping the power of states and imposing a one-size-fits-all plan on the nation. That will not work. And I'm very happy that the Democrats are celebrating the fact that we put in place a health care proposal in Massachusetts, an experiment. And I have one question for them. Why didn't any one of them or the president ever call me and say, 'What worked? What didn't?'"
He also added: "Not one Democrat called me and said, OK, 'Of what you did in Massachusetts, what would you do again? What would you do differently? What things worked? What things didn't work?"
"And I would have told them this, I'd have said, 'What you're putting in place at the nation is not only unconstitutional, it's bad law, it will not work. And even if it were perfect, which it's not, it's expensive."
The key moment occurs at the 10:15 mark below: