Another ghost from Mitt Romney's business past may be coming back to haunt him. Romney has long maintained close ties with Marriott International, and he led its audit board for several years, Bloomberg points out. During that time, Marriott instituted a tax maneuver it nicknamed "Son of BOSS," in which it used newly created partnerships to record a $71 million tax loss, even though the company actually profited. A court later struck down the maneuver, calling it a "scheme," "fictitious," "artificial," and an "illusion."
During Romney's tenure, Marriott also took deductions that eventually led to a $220 million settlement with the IRS, and reaped hundreds of millions from a fuel subsidy program that John McCain once criticized as a "scam." The company's effective tax rate at times fell as low as 6.8%. As an audit board member, Romney would have been deeply involved in approving these tax plans. He returned to Marriott in 2009, before leaving again last year. (Read more Marriott stories.)