The Michigan Supreme Court wants a lower court to explain why it dismissed a lawsuit challenging the unionization of 40,000 at-home child-care workers.
It sent the case back on Thursday to the state appeals court, which had ruled against three women with a six-word sentence in December.
The women are suing the state Department of Human Services, saying the union is illegal because child-care providers are not public employees.
The union is a partnership between the United Auto Workers and the American Federation of State, County and Municipal Employees. It gets a slice of the millions in state subsidies paid to providers who watch children from low-income families.
A separate lawsuit in federal court names the UAW and AFSCME as defendants.