Justices Reconsider Campaign Finance

Clement said the ads are not a good test, because they "closely resemble" the kinds of ads that the court specifically said in McConnell were "functionally equivalent to express advocacy."

But James Bopp Jr., arguing for Wisconsin Right to Life, said the law puts groups in an untenable position, because they want to lobby Congress on action that happens to occur during the blackout period.

"And we have in the First Amendment one of the four indispensable freedoms -- your right to petition the government," he said.

Bopp and Justice David H. Souter disagreed about whether the words in the ads could be judged outside of the political context, which is that Wisconsin Right to Life had been highly critical of Feingold's position on the filibuster and had made defeating him the group's priority.

"It is impossible to know what the words mean without knowing the context in which they are spoken," Souter said.

"There's absolutely no evidence that anyone in Wisconsin knew his position on the filibuster," Bopp replied.

"You think they're dumb?" Souter shot back.

Even Justice Anthony M. Kennedy, who was in the McConnell minority with Scalia and Justice Clarence Thomas, said the court looks at context when judging speech.

The decision in McConnell was complicated, and this one could be as well, especially if Roberts and Alito do not want to simply join their three colleagues and upset precedent so early in their tenures. Roberts said during the argument that he is "trying to see if there's a way of approaching this as-applied challenge in a way that doesn't require us to revisit" the prior decision.

The court found such a way recently, in its decision to uphold a federal ban on what opponents call "partial birth" abortion, to reverse course on its abortion holdings without technically upending seemingly contradictory precedents.