Several of the most politically active 501(c)(4) "social welfare" groups apparently failed to report to the Internal Revenue Service millions of dollars in spending on independent contractors involved in campaign advertising blitzes, according to the Center for Public Integrity.
Both liberal and conservative entities disclosed multiple six- and seven-figure expenditures on media buyers and consultants to the Federal Election Commission but did not include the information in IRS filings, which ask for a list of contractors that received more than $100,000 in compensation.
The pro-Republican Club for Growth and Crossroads GPS and liberal group Patriot Majority USA acknowledged the errors and said they planned to correct them. Other organizations that appear to have made similar omissions did not respond to the Center for Public Integrity's requests for comment.
One of the latter organizations, the 60 Plus Association, also appears to have significantly understated the level of its election spending in federal tax filings, the center also reports. The Virginia-based group advocates on senior issues and is largely funded by the conservative political network associated with billionaire industrialists Charles and David Koch.
The association told the FEC it spent about $4.6-million on political ads and "voter contact" calls in the run-up to the 2012 election but reported to the IRS $35,000 on "direct and indirect political campaign activities" for the entire 2012 fiscal year. A spokesman for the group did not respond to requests for comment.