2010 promises to be a busy political year in the United States as Democrats and Republicans battle for control of Congress in the November midterm elections.  A recent U.S. Supreme Court decision could have a profound effect on how election campaigns are waged.

The high court ruling in January removed long-standing bans on corporations and labor unions from running television and radio advertisements for or against specific candidates.

Corporations are still prohibited from donating directly to political candidates.  But a majority of the Supreme Court's nine justices accepted the argument made by attorney Ted Olson that severe limits on political contributions amount to an unconstitutional limit on free speech.  "Robust debate about candidates for elective office is the most fundamental value protected by the First Amendment's guarantee of free speech," he said.

The ruling was a major victory for conservatives and free speech advocates like attorney Floyd Abrams, a veteran of legal battles over the First Amendment to the U.S. Constitution that guarantees freedom of speech.  "If you really mean that speech is a good thing, if you really believe that the public ought to have a chance to hear all views and make up their own mind, there is no reason to limit the class or category of people or institutions who may be heard," he said.

A narrow majority on the high court decided that corporations and labor unions have as much right to express themselves through the political campaign process as individual citizens.

But the ruling has many critics who worry that corporations, unions and other special interest groups can now spend as much as they want running ads urging a candidate's election or defeat.

"This is a conservative Supreme Court decision; it is a Wall Street decision; it is a corporate decision.  And I think, over time, the American public is going to be just simply outraged by it," said Bob Edgar, President of Common Cause, an independent government accountability group based in Washington.

Edgar says that unleashing more corporate and labor union spending in political campaigns could intimidate members of Congress from supporting legislation that companies and unions oppose. "We need to recognize that money has influenced the debate here in Washington for too long.  And my guess is that what you are going to discover over the next several years is that the elected officials in the House [of Representatives] and Senate are going to end up serving special interests even more than they do today, and not the public's interest," he said.

It is concern shared by many Democrats in Congress, including Senator Dick Durbin of Illinois. "It will have a big impact on campaigns.  It will have a big impact on Congress because it really will increase the pressure that can be put on members of Congress for critical votes.  There is pressure already, but the pressure will be increased dramatically knowing that the corporation you say 'no' to in trying to fight off a new tax is the same corporation that can now spend a million dollars to beat you," he said.

Democrats in Congress hope to enact campaign contribution limits that will soften the impact of the Supreme Court decision.

They are pushing for disclosure requirements for corporations and unions that want to run ads, and they want to limit the impact of foreign corporations on U.S. elections.  Current laws prohibit foreign companies from buying political ads.  But there is concern that foreign companies could make use of their U.S. subsidiaries to take advantage of the Supreme Court ruling.

Republicans in Congress generally support the easing of restrictions on what they call political speech.

Senator Bob Bennett expects the ruling will help his opponents in an upcoming Republican primary in Utah.  But he says he accepts that. "They have promised the works, quote/unquote - television, radio, billboards, mail, the whole thing.  I really don't like it, but it is their constitutional right.  And there is nothing I want to do to prevent them from doing it, even though it makes my life very unhappy," he said.

The full impact of the Supreme Court decision will likely be felt during this year's congressional elections campaign.  Analysts say Americans can expect see to even more political ads than usual during the final weeks leading up to Election Day in November.