update on the ruling...

The January 21, 2010, decision:

http://www.msnbc.msn.com/id/34822247/ns/politics-supreme_court/
In a landmark ruling, the U.S. Supreme Court struck down laws that banned corporations from using their own money to support or oppose candidates for public office.
By 5-4 vote, the court overturned federal laws, in effect for decades, that prevented corporations from using their profits to buy political campaign ads. The decision, which almost certainly will also allow labor unions to participate more freely in campaigns, threatens similar limits imposed by 24 states.

It leaves in place a ban prohibiting corporations and unions from directly contributing funds to candidates for any use.

Strongly disagreeing, Justice John Paul Stevens said in his dissent, "The court's ruling threatens to undermine the integrity of elected institutions around the nation."

Justices Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor joined Stevens' dissent, parts of which he read aloud in the courtroom.

The justices also struck down part of the landmark McCain-Feingold campaign finance bill that barred union- and corporate-paid issue ads in the closing days of election campaigns.

http://www.msnbc.msn.com/id/35117174/ns/politics-white_house?GT1=43001

...the decision said corporations and unions could spend freely from their treasuries to run political ads for or against specific candidates.

In his dissent, Justice John Paul Stevens said the court's majority "would appear to afford the same protection to multinational corporations controlled by foreigners as to individual Americans."
Obama said corporations can "spend without limit in our elections." However, corporations and unions are still prohibited from contributing directly to politicians.