That would be incorrect. IRRC the term "political organization" is not used in the law or regulations etc. 501(c)(4) has long been used to promote things that can readily be understood as "political". The IRS has approved it long ago as you can see below.
Most of the below is from Case Western Reserve University law professor Laura B. Chisolm in a 1988 article for the Indiana Law Journal.
http://blogs.wsj.com/law/2013/11/26/the-history-of-the-501c4-exemption/
Direct support to a candidate is forbidden and so is obvious partisan activity (i.e., promoting one party over another).
Citizens United doesn't have a damn thing to do with this. There has never been a limit on the amount of money a corporation can contribute to 501(c)(4) orgs.
Citizens United allows corp to contribute to PACs, which are a different type of org and not covered by 501(c)(4).
Fern