How do we know that incumbents are afraid of super PAC spending because it will ...

cheese1756 on July 5, 2014 | parent | context | favorite | on: MayDay PAC

How do we know that incumbents are afraid of super PAC spending because it will create change and influence the population? Couldn't it just be that they are afraid of a super PAC dumping money into attack ads and an opponent's campaign if they go against the wishes of a special interest group?