This is an eloquent recitation of one of the bedrock principles of freedom upon which this nation was founded. And I do not think Jefferson overstated or exaggerated the principle. When the government forces a citizen to financially support the political assertions of someone with whom the citizen disagrees, then we have not a government of the people, but an immoral tyranny. It also probably does not surprise anyone to hear that such government action is unconstitutional. Violations of free speech include not only the suppression of some political opinion, but also forcing people to support speech with which they disagree.
Labor unions derive their power to collectively bargain from state and federal laws.
They use this power to justify forcing workers to pay union dues whether or not they want to be members. Much of these dues then go to support political activities that the workers may or may not agree with. In Lehnert , the Court declared that unions cannot constitutionally compel workers to financially support union activities unrelated to their collective bargaining role. The ruling in Lehnert thus entitles union members to a refund of the portion of their dues used for political lobbying and other electoral activities. Other cases have since extended this protection to members of the various state bars as well.