President Obama’s re-election campaign has spent weeks trying to drive home the point that Massachusetts was at the back of the pack in job growth under Gov. Mitt Romney. Now, a new campaign TV ad touts a stat on which Romney’s state surged to the front — per capita debt. “Number One,” a 30-second spot, claims Massachusetts debt grew $2.6 billion during Romney’s tenure between 2003 and 2007 to $18 billion, or $4,153 per person, according to Moody’s 2007 State Debt Medians cited in the ad. “First in debt. Forty-seventh in job creation. That’s Romney economics,” the ad says. The...