McCain, whose name has been synonymous with the push for campaign finance reform, also says, quoting, "I predict to you that there will be huge scandals associated with this huge flood of money."
McCain was referring to Citizens United, the court's 2010 ruling against limits on spending by independent organizations. The justices based their decision on freedom of speech principles.
A super PAC supporting former Massachusetts Gov. Mitt Romney ran negative ads against former House Speaker Newt Gingrich in Iowa. Gingrich says the spots substantially harmed his campaign. And Gingrich now is benefiting from similar spending by a group running anti-Romney ads in South Carolina.