There are still unanswered questions about the politically active 501(c)(4) "social welfare" groups. The anonymously funded entities' multimillion-dollar ad budgets helped to clog the airwaves last year.
How much did they really spend to intervene in the 2012 campaign? What kinds of sources supplied their money? What ties do they maintain with other nonprofit organizations or for-profit companies?
The IRS is now trying to address some of the unknowns by asking organizations to fill out a questionnaire about their finances.
The network of political groups headed by conservative industrialists David and Charles Koch spent millions of undisclosed dollars in last year's elections. Now, after failing to help Republicans win the White House or the Senate, the Koch brothers are re-examining the network, its goals and strategies.