"It's very hard to think that any candidate doesn't know the contributor who has enough money to give not only to himself or herself, but to any of his or her affiliates who are supporting him or her," said Sotomayor. "I mean, it's nearly common sense, hard to dispute."
Another point of contention is whether the aggregate spending limits are really having a pervasive effect, or involve only a relative few well-heeled givers. Justice Antonin Scalia suggested free speech applies equally, to rich and poor.
"I assume that a law that only prohibits the speech of 2% of the country is OK," he said somewhat sarcastically to Verrilli, who was arguing for the Federal Election Commission in defending the laws.
But Justice Stephen Breyer there is a free speech "positive" aspect to the restrictions.
"If the average person thinks that what he says, exercising his First Amendment rights, just can't have an impact through public opinion upon his representative, he says: What is the point of the First Amendment?"
Outside the court, supporters of the current restrictions held signs saying "McCutcheon = Corruption," and some demonstrators were dressed as green dollar bills.
"If the court were to strike down the contribution limits at issue in McCutcheon, the government will be back on the auction block to the highest bidders as it was in the Watergate scandals of the 1970s and the soft money scandals of the 1990s," said Fred Wertheimer, founder and president of Democracy 21, a longtime activist on campaign spending reform.
But McCutcheon himself, who attended the arguments, told CNN, "Getting rid of the aggregate limits is not about corrupting democracy-- it is about practicing democracy."
"This case is about freedom -- your freedom and my freedom -- to express ourselves openly and fully within our political system. And if there is one thing that we Americans believe with all our hearts, it is that freedom never corrupts."
If there was one area of agreement, it was the overall byzantine complexity of the issue. "This campaign finance law is so intricate that I can't figure it out," lamented Scalia at one point.
The case is McCutcheon v. Federal Election Commission (12-536).