This is really an interesting legal issue. There is a similar issue in Minnesota.
In Minnesota it involves child care workers. People leave their kids with daycare. It might be a mom operating out of her home, or a more formal setting. But the parents might also be eligible for certain state benefits to help pay childcare costs.
Based upon that, Minnesota's democratic governor determined that he had the authority to basically declare that a certain union was the "exclusive representative" of these child care workers, even though many of them are self employed, or are independent companies. The union isn't going to negotiate on behalf of the child care workers with anyone, since the party they work for is the parents of the children. Instead, they will "negotiate" with the state for more tax dollars to be allocated to help subsidize child care. Of course, the union wants union dues from each child care worker, or daycare center for this service, even though none of them are "employed" by anyone, but instead are independent contractors for the parents. And even though none of the child care workers got to vote on this union representation.
I think the Minnesota litigation was basically put on hold pending a Supreme Court resolution of this Illinois case.
I apologize if I've recited the basic facts of the Minnesota case incorrectly since I'm doing it strictly from memory of what I read in the paper a number of months ago, but I think I have the basic premise correct.