As a counterpoint to a lot of the outrage, it's worth noting that the rules around 501c4 organizations are fucked.
As Ezra Klein points out "The IRS was wrong to target the tea party. They should’ve gone after all 501(c)4s."
http://www.washingtonpost.com/blogs/wonkblog/wp/2013/05/10/t...
The fact that this has become a political issue is a huge failure of governance, not politics.