"This opinion represents a landmark victory for the American people in the effort to reform their political system," Sens. John McCain, R-Ariz., and Russ Feingold, D-Wis., and Reps. Christopher Shays, R-Conn., and Marty Meehan, D-Mass., said in a group statement.
"Now that the court has spoken, we must make sure that the law is properly interpreted and enforced."
In a 5-4 ruling he Supreme Court largely upheld the law, which amends the 1971 Federal Election Campaign Act, plugging the soft-money loophole and regulating campaign ads that influence a campaign.
However, a separate statement from Wayne LaPierre, president of the National Rifle Association, an organization that has long used soft-money campaign financing, said, "This is a sad day for the Constitution, but the 4 million members of the NRA will continue to be heard. That I can promise."