The case you linked refers to Beck, which is a ruling on the NRLA which as far as I can tell does not apply to the public sector.

Wikipedia points to Lehnert v. Ferris Faculty Association, which has:

"Non-chargeable expenses include: Lobbying, electoral, or other political activities not directly related to contract bargaining or implementation;[144] political or public activities aimed at winning a greater budget for the collective bargaining unit;[140] litigation or publications reporting on litigation that does not concern directly concern the bargaining unit;[145] and public relations efforts (including informational picketing, media purchases, signs, posters, and buttons) designed to enhance public respect for the workers' profession"

I'm not a lawyer and I'm not sure what the difference is between this upcoming case and that one. But it sounds like the supreme Court has already ruled that lots of the behavior I find objectionable is not chargeable as an agency fee to nonmembers.