(CNN) -- Opponents calling into question Mitt Romney's tenure as the chief executive of Bain Capital are "attacking the American way of life," according to former New Hampshire Gov. John Sununu, a top surrogate for Romney's presidential campaign.
Speaking on a conference call Tuesday, Sununu said he was outraged Democrats would attack Romney's track record at the private equity giant.
"I am amazed at listening to President Obama and Vice President Biden attacking free enterprise in general, and their specific attacks on Bain," Sununu said. "The free enterprise system is the American way of life, and when you attack free enterprise you're attacking the American way of life."
Over the past week and a half, Democrats have used web videos and television ads to paint Romney as a job killer during his tenure at Bain. They have focused on companies that were acquired by the company and later went bankrupt. Representatives for Obama's campaign have been careful to add they aren't attacking private equity as a whole, but rather trying to assess the "lessons and values" Romney learned while in the business.
Sununu did concede that Bain was "fair game" in the presidential campaign, but said Romney's record at the firm needed to be presented in its entirety, not in bits and pieces.