This is a case of bait-and-switch. Romney, in his convention speech, spoke of his plan to create “12 million new jobs,” which the campaign’s white paper describes as a four-year goal.

 But the candidate’s personal accounting for this figure in this campaign ad is based on different figures and long-range timelines stretching as long as a decade — which in two cases are based on studies that did not even evaluate Romney’s economic plan.  The numbers may still add up to 12 million, but they aren’t the same thing — not by a long shot.

 In many ways, this episode offers readers a peek behind a campaign wizard’s curtain — and a warning that job-creation claims by any campaign should not be accepted at face value. The white paper at least has the credibility of four well-known economists behind it, but the “new math” of this campaign ad does not add up.

 As readers know, we tend to judge more harshly claims in prepared speeches or ads that were the result of considered discussion by political aides.  

 Clearly, some clever campaign staffer thought it would be nice to match up poll-tested themes such as “energy independence,” “tax reform” and “cracking down on China” with actual job numbers. We just find it puzzling that Romney agreed to personally utter these words without asking more questions about the math behind them.