Yeah, the union agreement gives the union money whether or not you're a member. This was recently ruled illegal in the public sector (Janus v. AFSCME), because

Yeah, the union agreement gives the union money whether or not you're a member. This was recently ruled illegal in the public sector (Janus v. AFSCME), because of first amendment concerns (the state is forcing you to pay money for union lobbying). This hasn't resulted in a drop in membership, in no small part due to many unions adopting freakishly Byzantine opt-out measures, e.g. the ones where there's a certain window of 10 days a year that you can leave (computed relative to when you signed your union card, never advertised by the union — and if the employer even mentions these rights the union might attempt legal action under California law which forbids their employer from doing anything to "deter or discourage public employees from becoming or remaining members").