In a 5-4 vote, the court ruled that Congress went too far when it loosened fund-raising restraints for candidates facing millionaires who invest in their own campaigns.

The court's majority declared that the campaign-finance double standard violated First Amendment free-speech guarantees.

"The argument that a candidate's speech may be restricted in order to level electoral opportunity has ominous implications because it would permit Congress to arrogate the voters' authority to evaluate the strength of candidates competing for office," Justice Samuel Alito wrote for the majority.

The decision, arising from a New York congressional race, marks the second time in as many years that the court has undercut a 2002 campaign-finance law coauthored by Sen. John McCain (R., Ariz.).

The now-diminished law is the signature Capitol Hill accomplishment for McCain, the GOP presidential candidate.

Dubbed the "millionaire's amendment," the provision struck down yesterday was billed as a way to level the campaign playing field. It did not restrict how much money the wealthy candidate could spend.

"The millionaire's amendment does not impose any burden whatsoever on the self-funding candidate's freedom to speak," Justice John Paul Stevens wrote in dissent, adding that "it does no more than diminish the unequal strength of the self-funded candidate."

The opinion broke down along predictable fault lines.

Chief Justice John G. Roberts and Justices Antonin Scalia, Anthony Kennedy and Clarence Thomas joined Alito in striking down the provision. Justices David Souter, Ruth Bader Ginsburg and Stephen Breyer joined Stevens in the main dissent.

The provision affected candidates for the House and the Senate differently. The New York businessman who challenged the law, Jack Davis, was a failed House candidate.

In House races, the provision kicked in once the presumed millionaire spent $350,000 of his or her own money. The opponent then could collect larger campaign contributions, with a tripling of the usual $2,300 limit on individual contributions.

The broader effects of Davis v. Federal Election Commission may unfold slowly.

Sen. Russell D. Feingold (D., Wis.), who coauthored the overall campaign-finance bill with McCain, said the decision left intact key elements of the 2002 law, including a ban on "soft money" - unlimited donations, even from corporate and union treasuries, for voter mobilization and party-building efforts.

Dozens of candidates have been eligible for the millionaire's amendment provisions. They include then-Senate candidate Barack Obama in 2004.

For the Supreme Court's opinion, go to: http://go.philly.com/

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