LONG BEFORE THE KOCHS AND THE BAGGERS...

conservatives have been abusing the tax-exempt status given to educational groups for decades.  A good example from the 50s is Clarence Manion:

Where every aspect of life is something to be "politicalized,"
it is not easy to distinguish political organizations from
those that are labeled religious or educational. The Manion
Forum, instituted by Clarence E. Manion, former Dean of the
Notre Dame Law College, is a case in point.

The Forum, which calls itself a "non-partisan, non-profit
organization," was set up in 1954, under the laws of Indiana,
as an "educational trust." Such terms as forum, non-partisan,
and educational incline us to expect that this organization
will stimulate a careful weighing of issues and some all around
consideration of public affairs. Yet the Manion Forum
—which conducts a weekly radio program, publishes a
monthly newsletter, publishes various tracts and pamphlets,
and encourages the formation of "Conservative Clubs"
throughout the country—is as dedicated to implanting the
far-right doctrine as if it frankly declared itself to be engaged
in political propaganda.

An issue of the Wall Street Journal carried the Forum's
statement of purpose: to "wage war" against "(1) the
confiscatory, Marxist income tax; (2) wanton foreign aid
squandering; (3) Socialistic 'public power'; (4) destruction
of states' rights; (5) futile conferences with Kremlin gangsters;
(6) ridiculous budgets; (7) federal aid to education,
and (8) unrestrained labor bossism."

Obviously, the terminology used here would not be found
in an educational brochure. It is the type of terminology that
abounds in the writings of both the Left and the Right extreme;
and it amounts to an announcement that rage, having
parented a "cause," is out to demolish an enemy.

SOURCE:THE STRANGE TACTICS OF EXTREMISM, HARRY and BONARO OVERSTREET (1964) P.226