Doubling down on comments he made earlier in the week, Sen. John McCain (R-Ariz.) on Sunday's "Meet the Press" once again denounced the Supreme Court's 2010 Citizens United decision for unleashing the flood of money now "washing over politics."

McCain is a key backer of former Massachusetts Gov. Mitt Romney, whose campaign and supporting super PACs have outspent former House Speaker Newt Gingrich and his allies on television advertisements by a 4-1 ratio. But asked whether he condemned super PACs -- organizations that can accept unlimited donations from corporations, individuals and unions for independent campaign spending -- McCain said, "I condemn them on all sides and I condmen United States Supreme Court for their naivete" in the Citizens United decision, which he described as an "outrage."

Citizens United struck down limits on corporate spending set forth in a 2002 campaign finance law that McCain sponsored and helped pass through Congress. Soon thereafter, a federal appeals court, relying on Citizens United's logic, enabled the creation of super PACs by striking down limits on individual spending in campaigns.

Romney has long voiced agreement with Citizens United, famously rebutting a heckler complaining about the Court's extension of First Amendment rights to corporate speech by saying, "corporations are people, my friend."

"Now we have a casino owner and his wife," said McCain on Sunday, putting "10 million dollars into the race" to keep Gingrich's candidacy alive. Sheldon Adelson, the casino owner and Gingrich's friend, "makes a lot of his money out of Macau," McCain said, raising the specter of foreign money in American politics. Beyond his business success, Adelson is known for his right-wing views on Israeli politics, manifested through his strong support for Israeli Prime Minister Benjamin Netanyahu.

"On both sides we have these incredible amounts of money and I guarantee you there will be a scandal," McCain continued. It was unclear, however, whether by "both sides" he meant Republicans and Democrats or Gingrich and Romney. Pro-Romney groups have spent twice as much as pro-Gingrich groups in Florida.

McCain made similar criticisms of the post-Citizens United landscape on Wednesday during a conference call to voice his support for Romney. "I think the outside super PACs and others is so disgraceful that I'm ashamed of the United States Supreme Court in their decision on United," McCain said.