Two-thirds of Americans who are aware of the groups’ emergence in politics say they will have a negative impact on elections, according to a Pew Research Center poll. Super PACs can spend unlimited amounts on behalf of a candidate.
Almost half of voters, however, have not heard of their existence. Super PACs sprang up after a 2010 Supreme Court ruling (Citizens United v. Federal Election Commission) that said institutions from corporations to unions have similar free-speech rights as people in campaigns – if super PACs are run independently of campaigns (a big if).