News conferences were scheduled and telephone briefings were penciled in, but Washington advocacy groups were disappointed yet again Wednesday: The Supreme Court did not issue its long-awaited decision on campaign finance laws.

This is a vigil of the kind to be found only in Washington. Legal groups, political parties and court-watchers have been waiting for months to learn whether the high court will uphold a ban on corporate spending on elections, or if instead it will open the gates to unlimited donations from well-financed companies and unions.

Groups on both sides have dutifully notified the media before each potential court release date, announcing possible news conferences or briefings in reaction to the anticipated ruling. One coalition of Midwestern liberal groups has even gone to the trouble of preparing a Web site, http://www.movetoamend.org, specifically aimed at fighting a decision that has yet to be announced.

"We keep planning the news conference but then the news doesn't happen," said Tara Malloy, associate counsel for Washington-based Public Campaign, which favors public financing of political elections. "How many times can you get all keyed up?"

The Supreme Court stunned lawyers on both sides of the campaign finance debate last summer when it announced that it would examine whether previous statutes and court decisions violated the Constitution by restricting political spending by corporations. The move delayed a decision on whether Citizens United, a conservative group, violated campaign finance law by funding a 2008 film criticizing then-Sen. Hillary Rodham Clinton.

The case is particularly important given the shifting mood of the electorate and the midterm elections that are just 10 months away. Those in favor of campaign finance restrictions fear that the court is poised to upend decades of precedent by allowing corporations, and perhaps unions, to spend as much as they want for and against candidates.

The sense of impending doom is evident in the tide of news releases on the topic in recent months. The decision could "open the door to the corrupting influence that would flow from such expenditures," said a joint release issued Tuesday by the Campaign Legal Center, Common Cause, Democracy 21 and Public Campaign.

"There is great fear that the court will strike a serious blow against American democracy," said Ben Manski, executive director of the Liberty Tree Foundation of Madison, Wis., which helped create the Move to Amend site. "There are reasons to be very concerned."

Mary Boyle, communications director for Common Cause, said her group has been on high alert, awaiting a ruling, since mid-November. News briefings were scheduled on both Tuesday and Wednesday this week because the court was issuing rulings on those days; by Wednesday afternoon, Boyle was canceling airplane reservations for next week, when additional rulings are scheduled for release.

"It seems that they're having a hard time reaching agreement," Boyle said. "Obviously the longer this goes on, the further we get into the campaign season."

Bradley A. Smith, chairman of the Center for Competitive Politics, which favors looser restrictions on campaign spending, said he tries to refrain from speculating on the reasons for the continued delay but concedes that it has him puzzled.

"You gear up when you think it might come out because you have to be ready, but I think most people are surprised that it's taken so long," Smith said.