The NYT reports that Indiana governor Mitch Daniels is pushing legislation that will require workers who support a union to pay extra money to support the cost of representing workers who don't want to pay for their representation. Under federal labor law, a union is required to represent all the workers in a bargaining unit, whether they opt to join the union or not. This means not only that all workers will receive the full pay and benefits negotiated by the union, but also that the union is required to represent workers who face any sort of disciplinary action.
Since the union is legally obligated to represent all workers in the bargaining unit, in most states workers are able to sign agreements with management that require all workers to pay for this representation. However, some states infringe on workers' freedom of contract and prohibit such agreements with management. These states require the workers who join a union to pay for the representation of workers who opt not to join.
This restriction on the freedom on contract, which passes under the euphemism "right to work" is being pushed by Indiana governor Mitch Daniels. According to the article, it is likely to be approved by Indiana's Republican legislature.
It would have been helpful if this piece had made a point of noting that this legislation requires workers who support a union to pay for the benefits received by the workers who opt not to join. It is also important to note that no one is ever required to join or pay for a union they don't like. As every libertarian knows, a person who doesn't like unions is completely free to work for an employer where workers are not represented by a union.