While most political eyes are trained on the Republican nomination contest, there is another fight going on at the same time: to define Mitt Romney. There are two very distinct storylines on Romney, one from his Republican rivals and one from the Obama campaign and its supporters. What’s fascinating is that these narratives could cancel each other out, creating a real advantage for the former governor.

Here’s how it could work. Romney’s greatest vulnerability among Republicans is suspicion about the strength of his conservative convictions. His opponents rarely miss a chance to hit him for being a flip-flopper — on health care, taxes and abortion. Romney, they say, is really a sheep in a wolf’s costume. Paradoxically, these attacks, while clearly effective with Republicans, actually help Romney with swing voters. They have no use for Michele Bachmann, Herman Cain, Rick Perry, Rick Santorum or Newt Gingrich -- too conservative. Swing and independent voters are looking, as always, for a more centrist candidate: conservative on economic issues, but moderate on social issues. Every time Romney is attacked for being insufficiently right-wing, it sends a message of reassurance to independents.

Obama’s strategists inside and outside the campaign recognize this danger. Their super PAC, Priorities USA, sent out a memo this week to “interested parties.” In it, they made clear that the Obama negative track on Romney isn’t about his flip-flops, but where he’s landed: as a right-winger in good standing on issues like abortion, overturning Roe vs. Wade, and defunding Planned Parenthood. Obama’s strategists wish the Republican critique would go away, so they can focus on Romney’s destination, not his journey. Problem is, important voters are learning that maybe Romney isn’t so conservative after all, and in an electorate longing for an alternative to Obama, even Romney’s flip-flops could be reassuring.