His was an efficient and effective state policy; Mr. Obama’s was “a power grab by the federal government.”

He tried to justify this with a history lesson on federalism and state experimentation, but, in fact, he said nothing about what makes Massachusetts different from its neighbors or any other state. And why would he immediately repeal the Obama mandate if elected president? Because Mr. Obama wants a “government takeover of health care,” while all he wanted was to insure the uninsured.

That distinction makes no sense, and the disconnect undermines the foundation of Mr. Romney’s candidacy. At heart, he is still the kind of old-fashioned northeastern Republican who believes in government’s role while trying to conceal it under a thin, inauthentic coating of conservative outrage. But in its blind abhorrence of President Obama, the party has also left behind former centrists like Mr. Romney, and it is unlikely that any amount of frantic pandering about the free market will change that. He is trapped not only between the poles of his party but between eras, a candidate caught in an electoral time warp.