The idea is that any payment of union members to politics may not be done by payroll deduction and that any payment must be initiated by the employee.  A union member must opt in rather than being required to,opt out.

For some years the names of people signing an initiative are a matter of public record.  s

So by adding your name to the names of people who already agree with opt in means it should be easy to qualify this idea election after election.  In California it only costs $250 to submit a list of names to the state to qualify an initiative.  It costs the unions a lot to defeat this initiative, money that will not be spent advancing their agenda.