Washington ? It’s not every day the National Rifle Assn. and the American Civil Liberties Union are outraged by the same Supreme Court decision.

The two organizations are often used to represent opposite poles of American politics, the gun-toting right and the liberal left. But both groups hated Wednesday’s unexpectedly broad ruling by the court to uphold the major provisions of the McCain-Feingold campaign finance law.

Reformers have been trying to squeeze the influence of money out of politics for at least 100 years, but Wednesday’s ruling was either one of the boldest steps yet or a terrible overreach, depending on which side was analyzing the case. Surprise at the scope of the ruling was just about universal, however. Even many proponents of the campaign finance law had expected the court to use the First Amendment to strike down new limits on political advertising on television.

But the prevailing justices — with Justice Sandra O’Connor in the decisive role, as she is so often — cast a deeply disgusted eye on the entire political process, finding “corruption, and in particular the appearance of corruption,” almost everywhere they looked. Even efforts by political parties to register voters, identify supporters and urge them to the polls — activities once extolled in civics classes — were seen as opportunities for corruption if large donors were allowed to pay for such projects as a way of currying favor with elected officials.

The problem with critics of the law, the majority declared, is that they “conceive of political corruption too narrowly.”

This attitude took the 5-to-4 majority well beyond earlier limitations on political advertising, in the judgment of several First Amendment experts. And so a broad range of advocacy organizations denounced the decision as a historic attack on the right to free speech. Under the ruling, groups wishing to use television ads to criticize — or even mention — federal candidates during the decisive months of an election year must comply with an array of regulations before they can say their piece.

“The notion that the government can tell an organization like the ACLU when and how it should address important civil liberties issues is a form of censorship masquerading as campaign finance reform,” ACLU Executive Director Anthony Romero said in a statement reacting to the ruling.

Wayne LaPierre, head of the NRA, called the ruling “the most significant change in the First Amendment since the Alien and Sedition Acts of 1798, which tried to make it a crime to criticize a member of Congress. … This whole thing from the start has been an inside deal among politicians to stop criticism, whether it comes from us or from the Sierra Club.”

The court explained itself by saying that Congress was the best institution for sorting out election rules and for balancing the importance of free speech against the need for reform. But that theory also was hotly debated Wednesday. To critics of the ruling, including dissenting Justice Antonin Scalia, giving congressional incumbents a virtually free hand to set the rules of future elections is like letting the reigning Scrabble champion rewrite the dictionary.