Of course, no party leader or strategist ever wants to admit — even to himself — that he owes his victory solely to the public’s disdain for the status quo, any more than a great general would want to believe that he won the decisive battle because his enemy ran out of bullets. Once you win, the human tendency is to credit the gravitational force of your own ideas, to assume that you made a more compelling and more substantive case than you actually did.
I'm afraid I can't help nitpicking a little. Bai thinks, correctly, that reading the Constitution on the House floor is symbolic; alas, he believes that the business of citing specific Constitutional authority is "not-so-symbolic." He's wrong; it's entirely for show, as is the repeal vote scheduled on health care. Well, the latter is real legislative action, but since it has no chance to go anywhere beyond the House it's really more symbolic than substantive. The Constitutional authority thing is purely symbolic.
Bai is also on shaky ground when he says that "voters endorsed the Tea Party ideal of a radically more parsimonious federal government," even though he qualifies it nicely by noting that "they haven’t yet gotten their heads around the excruciating choices it entails — or even the relatively easy ones. And that’s not really much of a mandate, when you think about it." Truth is, we don't really even know if the first half of that statement is true. It's also not really true that Barack Obama and the Democrats "came to enact a series of expensive new programs without ever really bothering to explain to the public why such investments were necessary or how they would be paid for." They may not have been successful with those explanations (although I wouldn't put it that way), but they certainly did "bother" to try to make their case.
I could go on nitpicking, but that's not really very nice of me. It's a good piece. He doesn't quite say that mandates are all fiction, but he's most of the way there, and the point he makes that winners are apt to believe in their own fictions is a good one. Of course, sometimes the fiction becomes true in a sense, if everyone believes it. It would still be a fiction to describe that sort of mandate as what the voters said, or wanted.