If you don't have time at the moment to read the whole decision in UAW v. Green, holding that Michigan's right to work law applies to the state's civil service employees, try this for a start:
From the majority opinion:
Part of the law in this area is settled, and part remains in flux. What is settled is that a government employer cannot force a dissenting worker, as a condition of employment, to financially support political causes of the union. However, the government employer may require the employee to pay a fee for the union’s costs for collective bargaining, as long as the fee is not used to advance political or ideological causes to which the worker objects. The question that remains in contention is how a union accounts for that portion of an agency fee that is spent on constitutionally permissible collective bargaining, versus unconstitutional expenditures on politics, how an employee may pursue the question of how fees are spent, and to what extent a union must reveal its expenditures. Those who oppose compulsory union fees assert that there is no adequate system to account for whether the fees are used only for collective bargaining and that, in reality, as a condition of remaining employed, employees must financially support political causes, which violates their First Amendment rights of free speech and political association. Those who support mandatory agency fees contend that failing to require payments from each employee permits “free riders” who pay nothing for collective bargaining, but who enjoy the benefits of union-backed negotiations, and that the methods used to determine how agency fees are spent interfere with union support of political and other causes, thus infringing on their rights of free speech and association.
Michigan has decided to leave the fray. With PA 349, the Legislature has made all contributions to public sector unions voluntary, thus removing political and ideological conflict from public employment, and eliminating the repeated need to decide, on a case-by-case basis, whether unions have properly allocated funds. The government as employer may no longer require public employees to pay money to unions its politics or ideological causes the employees oppose, and, at the same time, unions will no longer have to be wary of potential challenges to their financial contributions and may spend voluntary member dues as they see fit, without government oversight.
From the dissent (in a footnote):
The majority acknowledges that “[t]he Legislature possesses the broad power to enact laws relative to the conditions of all employment, whereas the CSC possesses the narrow power to regulate conditions of CSC employment.” (Emphasis in original.) If this specific power grant to the CSC must give-way whenever the Legislature disagrees with the CSC’s policy choice, article 11, § 5’s empowerment of the CSC is purely illusory.