President Obama says he can't imagine "anything more devastating to the public interest" than the Supreme Court's decision to ease limits on campaign spending by corporations and labor unions.
He also suggested in his radio and Internet address Saturday that the ruling could jeopardize his domestic agenda.
In the 5-4 decision Thursday, the high court threw out parts of a 63-year-old law that said companies and unions can be prohibited from using their own money to produce and run campaign ads that urge the election or defeat of particular candidates by name.
"This ruling opens the floodgates for an unlimited amount of special interest money into our democracy," the president said. "It gives the special interest lobbyists new leverage to spend millions on advertising to persuade elected officials to vote their way — or to punish those who don't."
Mr. Obama said that means lawmakers who stand up to Wall Street banks, oil companies, health insurers and other powerful interests could find themselves under attack at election time.
"I can't think of anything more devastating to the public interest," he said. "The last thing we need to do is hand more influence to the lobbyists in Washington or more power to the special interests to tip the outcome of elections."
The ruling came out as lawmakers make re-election plans and as Mr. Obama's Democratic Party feels the pressure from losses in New Jersey, Virginia and in Massachusetts, where Republican Scott Brown came from behind to win a Senate seat on Tuesday that Democrats had held for decades.
Mr. Obama said the decision will make it harder to enact financial, tax, health care and energy changes.
This program aired on January 23, 2010. The audio for this program is not available.