“Our members are proud to be part of [the organization]” — Marc Short, President of Freedom Partners, a Koch brothers-backed, tax-exempt outfit profiled by Politico on Thursday.

Interviewed for a Politico story on his previously unknown tentacle of the Kochtopus, Short showed off federal tax forms demonstrating how Freedom Partners funneled $236 million last year into efforts to defeat President Obama and make Congress a wholly-owned subsidiary of the Kochs and their ultra-conservative allies.

Only one group, Karl Rove’s notorious American Crossroads and Crossroads GPS, spent more — at $300 million.

Freedom Partners’ money was passed through established and high-profile groups like the National Rifle Association and the U.S. Chamber of Commerce, with hefty lists of individual and corporate members, and shadowy, Koch-linked groups whose membership — if any — is unknown. The recipients spent it on television commercials, online ads, direct mail and other efforts to promote the Kochs’ worldview.

Freedom Partners and their friends didn’t get all their candidates elected or all their opponents defeated — not by a long shot — but they’re still getting a return on their investment. In fact, if you’re wondering why congressional Republicans keep voting to defund Obamacare, look at the $115 million that Freedom Partners donated to the Center to Protect Patient Rights (CPPR), a Koch front devoted to undoing the President’s health care initiative. Every “no” voter on Obamacare knows he or she is a potential beneficiary of future CPPR spending.

But to get back to the laugh interest here — for all their professed pride in what Short called their commitment “to restore what they view are free markets in a free society in America” Freedom Partners’ donors remain a big secret. Because the group operates under Section 501 (c)(6) of the Internal Revenue Code, the same section reserved for trade associations like the U.S. Chamber, its donors do not have to be disclosed.

And for all his bluster about pride, Short isn’t about to disclose them.

Jon Stewart and Stephen Colbert ought to have a blast with this one.