The Supreme Court reinterpreted the law about how money from corporations and unions could be spent on campaigns. Super PACs and other outside groups made possible by the court's decision spent more than $1 billion on advertising in federal races through Election Day, according to a Center for Public Integrity analysis.The Center for Public Integrityhttp://www.publicintegrity.org/authors/center-public-integrityhttp://www.publicintegrity.org/2012/12/28/11981/best-2012-election-coverage