Former ambassador to China and Republican presidential candidate Jon Huntsman could have been the greatest threat to the president’s re-election, Obama’s campaign manager claimed Tuesday morning.

“I think Huntsman would have been a tough general election campaign,” Jim Messina said at a breakfast event organized by the Politico website.

The fact that Huntsman is widely considered a “moderate” may have played into Messina’s concern. Against Mitt Romney, “Barack Obama won moderates by 15 points,” Messina explained.