Sheldon Adelson, chairman of Las Vegas Sands, is chipping in $5 million for a Gingrich-aligned SuperPAC to run “King of Bain: When Mitt Romney Came to Town” in 30-second ad spots in South Carolina. The tone of the trailer is reminiscent of the Swift Boat Veterans for Truth spots against John Kerry.

As devastating as the spots may prove, Adelson’s money comes with liabilities. From a New York Times piece on Adelson: “His main source of income, casinos, could upset some social conservatives. That he operates in China could rankle isolationist voters, while some of his views on Israel are hawkish by mainstream Republican standards. Mr. Adelson’s company, Las Vegas Sands, also faces a federal investigation for possible violations of a federal antibribery law, relating to operations in the Chinese gambling district of Macau, the company acknowledged last year. The company has said the investigation stems from the allegations of a disgruntled former employee.”

Of course, all of this campaign spending is being done, with a wink, outside the official candidate committees.