No American should be compelled to financially support the promotion of beliefs to which he or she does not subscribe.

This week the U.S. Supreme Court struck a blow for this important principle by ruling that non-union workers may not be forced by contract to pay full union dues if some of those funds are used for political purposes.The ruling grows out of a case that centered on "agency shop" agreements. Under such an agreement, non-union employees at a unionized company must pay the union a fee to compensate the union for its collective bargaining activities on their behalf. Usually, the fee is equal to union dues, and failure to pay can result in dismissal.

Though the Supreme Court has now ruled that unions may not charge non-members for political activities not related to collective bargaining or other workplace activities, the ball is still in the court of the 10 million Americans covered by agency shop agreements.

First, those workers still need to insist that unions set up the bookkeeping procedures needed to establish what portion of union dues is used for collective bargaining and what portion is devoted to lobbying.

Second, they need to demand lower fees from the unions. Though such workers stand to gain not only more money but also more freedom from the new Supreme Court ruling, the decision won't enforce itself.