Whether you have to pay dues depends on your union contract. It's fair for everyone to support the union and pay dues – since everyone gets the wages, benefits, and protections in the union contract AND the union is required to represent every worker covered by the contract. With most unions, members don't start to pay dues until they vote to approve their first contract. People only vote for a contract that is worth a lot more than the cost of dues.
How and whether public workers pay dues is decided by state laws and rules.
Don't I have a Right-to-Work? This state does not have a Right-to-Work law. "Right-to-Work" (for less) means that you cannot be forced to join a union or pay dues. It does not mean that workers cannot build a union. It definitely doesn't mean that anyone has a right to work (usually the opposite – that the bosses have all the rights). Some states passed Right-to-Work law to make unions weaker. Bosses use it to divide workers and encourage workers not to belong to the union. In states that have it, there are fewer unions and workers have many fewer laws protecting them.
What if my religious beliefs prevent me from joining a union or paying dues? The National Labor Relations Act (NLRA) says that members of churches and other faith groups that do not believe in joining or supporting unions do not have to join the union. They may have to pay the same amount as union dues to a (non-religious, non-union related) charity. Read your union contract (usually under dues and dues deduction). If the contract doesn't list eligible charities, then you can choose one.
I don't want to pay dues because I don't like the politicians that the union supports. Companies have spent a lot of money to try to convince workers that their dues are wasted in politics. Companies would be happy for unions to stay out of politics (and leave it to them)! Unions work hard to get politicians to pay attention to working families – for higher minimum wages, for family medical leave, a fair workers' compensation system, and enough inspectors to protect workers health and safety. Most dues pay to run your organization. The money from dues for political work is tiny. Most unions have a political action committee, which decides when to be involved in politics. You can join the political action committee to influence how your dues money is spent. If you are paying dues anyway, why not get involved in your union? It is your only chance to have a real say at your job.
Union Membership and Dues Systems:
Closed shop This usually refers to a system in which every worker is required to join the union or pay the same amount of money as dues. Another meaning of closed shop is a workplace where only union members can be hired. This is illegal, except in union hiring halls, which are allowed to demand union membership.
Union shop After being hired, workers have to join the union and pay dues.
Fair Share/Agency shop Workers either join the union or pay an "agency," "representation," or "fair share" fee. Usually, this is close to the cost of dues. Workers who do not join are still represented by the union and the fee helps to pay for the costs of contract negotiations, research, lawyers, representing workers, and handling grievances. It's fair that everyone pay to run the union, since all workers get the benefits, raises, and protections in the contract.
Open shop Workers can join the union and pay dues or choose not to join the union and pay no dues. Non-members get all the rights, protections, pay, and benefits under the contract negotiated by the union and the union has to represent non-members in grievances or discipline.
Maintenance of Membership Union members can drop out only during a certain period of time, usually right before the contract ends. The contract will say how and when members can drop out.