Cain ad: Tax code is a 'version of slavery'

In a campaign ad touting his "9-9-9" tax plan, GOP presidential hopeful Herman Cain claims that the "American tax code is the 21st century version of slavery."

Cain's ad, released Wednesday, is intended to explain the three "9's" of his plan: "9 percent corporate flat tax, 9 percent personal flat tax, 9 percent national sales tax."