WASHINGTON — The Supreme Court on Tuesday seemed prepared to strike down a part of federal campaign finance law left intact by its decision in Citizens United in 2010: overall limits on direct contributions from individuals to candidates.
The justices seemed to divide along familiar ideological lines, and they articulated starkly different understandings of the role of money and free speech in American politics.
“By having these limits, you are promoting democratic participation,” Justice Ruth Bader Ginsburg said. “Then the little people will count some and you won’t have the super-affluent as the speakers that will control the elections.”
Justice Antonin Scalia responded, sarcastically, that he assumed “a law that only prohibits the speech of 2 percent of the country is O.K.”
Chief Justice John G. Roberts Jr., who probably holds the crucial vote, indicated that he was inclined to strike down overall limits on contributions to several candidates, but perhaps not separate overall limits on contributions to several political committees.
At a news conference Tuesday afternoon, President Obama said the case had the potential to destroy what was left of campaign finance regulation.
“The latest case would go even further than Citizens United,” he said. “It would say anything goes: there are no rules in terms of how to finance campaigns.”
The case, McCutcheon v. Federal Election Commission, No. 12-536, is a sort of sequel to Citizens United, which struck down limits on independent campaign spending on television advertisements and the like by corporations and unions. The new case is an attack on the other main pillar of federal campaign finance regulation: limits on contributions made directly to political candidates and party committees.
The case was brought by Shaun McCutcheon, an Alabama businessman, and the Republican National Committee. It is in one way modest and in another ambitious. It does not attack the familiar basic limits on contributions from individuals to candidates or party committees. The $2,600 cap on contributions to a given candidate in each election, for instance, is not at issue in the case.
Instead, the challengers take issue with separate overall limits of $48,600 every two years for individuals’ contributions to all federal candidates and $74,600 to political party committees. (Federal law continues to ban direct contributions to candidates or political parties from corporations and unions.)
“These limits,” said Erin E. Murphy, a lawyer for Mr. McCutcheon, “simply seek to prevent individuals from engaging in too much First Amendment activity.”
Solicitor General Donald B. Verrilli Jr. responded that the aggregate limits were an important tool to prevent circumvention of the base limits. Allowing multiple contributions to interlocking political committees affiliated with candidates and parties could, he said, effectively funnel large sums from individuals to support given candidates.
“Aggregate limits combat corruption,” he said.
The court’s more liberal members outlined various ways the base limits could be avoided. Justice Elena Kagan said it would be possible to write checks for $3.5 million to various entities in the hope the money would find its way to a candidate. “You give $3.5 million,” she said, “you get a very, very special place at the table.”
Justice Samuel A. Alito Jr. responded that the proposed end runs were fanciful.
“What I see are wild hypotheticals that are not obviously plausible and certainly lack any empirical support,” he said.
Justice Stephen G. Breyer repeatedly suggested that the case should be returned to a lower court to develop evidence on these points, but his proposal did not seem to gain traction.
Should the court agree that some overall limits are unconstitutional, the decision could represent a reassessment of a basic distinction established in a 1976 decision, Buckley v. Valeo, which said contributions may be regulated more strictly than expenditures because of their potential for corruption.
Independent spending, the court said, is political speech protected by the First Amendment. But contributions may be capped, the court said, in the name of preventing corruption.
The effect of the distinction is to allow unlimited spending from rich people, corporations and unions so long as the spending is not coordinated with the candidate they support. Several justices suggested that it makes no sense in such an environment to limit direct contributions to candidates and parties.
“It’s not that we’re stopping people from spending big money on politics,” Justice Scalia said.
Justice Anthony M. Kennedy contrasted two people.
“One person gives an amount to a candidate that’s limited,” he said. “The other takes out ads, uncoordinated, just all on his own, costing $500,000. Don’t you think that second person has more access to the candidate?”
Mr. Verrilli said the court’s campaign finance jurisprudence treated the two kinds of expenditures differently.
Justice Kagan acknowledged the point but said the solution was not to deregulate contributions. Rather, she said, it is to rein in independent spending.
“If this court is having second thoughts about its ruling that independent expenditures are not corrupting, we could change that part of the law,” she said, to laughter.
Chief Justice Roberts returned repeatedly to a possible distinction between the two kinds of overall limits. He said he accepted the possibility of circumvention where multiple committees were involved but could not see why individuals could not give to any numbers of candidates.
“The effect of the aggregate limits is to limit someone’s contribution of the maximum amount to about nine candidates,” he said. “Is there a way to eliminate that aspect while retaining some of the aggregate limits?”
Ms. Murphy did not seem eager to win only half of her case.
The chief justice asked a similar question of Mr. Verrilli. Would it be possible, he wanted to know, to address circumvention “while at the same time allowing an individual to contribute to however many House candidates he wants to contribute to?”
Mr. Verrilli conceded that the current limits forbid some contributions of that kind. “That’s true,” he said. “We can’t help but acknowledge that. It’s math.” But he said the limits were permitted by the First Amendment.
Chief Justice Roberts disagreed.
“You could not have a rule that says The Post or The New York Times can only endorse nine candidates,” he said.
Justice Alito at one point suggested he might endorse the chief justice’s approach. “These aggregate limits might not all stand or fall together,” he said.
Last year, a three-judge panel of the Federal District Court in Washington upheld the overall limits, saying they were justified by the need to prevent the circumvention of the basic limits.
“Although we acknowledge the constitutional line between political speech and political contributions grows increasingly difficult to discern,” Judge Janice Rogers Brown wrote for the court, “we decline plaintiffs’ invitation to anticipate the Supreme Court’s agenda.”
The court led by Chief Justice Roberts has so far been consistently hostile to campaign finance limits in its half-dozen decisions in argued cases on the subject so far. The five more conservative justices have voted together in all of those cases, though Chief Justice Roberts and Justice Alito have taken a more incremental approach than the bolder one called for by Justices Scalia, Kennedy and Clarence Thomas.