These days, presidential candidates are not just raising money for their own campaigns. They are also raising money for outside groups with generic sounding names like Priorities USA, Right to Rise and Our American Renewal. These are Super Pacs (political action committees), affiliated with each outside campaign but nominally independent. In 2012, they were helpful appendages. This year, heading into 2016, they are becoming fully fledged substitutes for campaigns, taking over functions including opposition research, polling and even knocking on doors. Super Pacs are just five years old. Like most developments in modern campaign finance law, they were created by accident through judicial decisions, not by legislation.
First, in 2010 the Citizens United supreme court decision struck down restrictions on independent expenditures in campaigns by nonprofits. Citizens United was followed the same year by a decision by the DC circuit court of appeals in a case called SpeechNOW, which said political groups that sought to make only independent expenditures could not be subject to federal campaign contribution limits.
These two decisions combined to create “super” versions of previously existing political action committees, that would make expenditures independently of the candidates they supported and thus could raise as much money as they wanted. In other words, one donor can fund an entire Super Pac.
Full Article: When is a campaign not a campaign? When it’s a Super Pac | US news | The Guardian.