As noted in this previous post, the Supreme Court’s decision today in Harris v. Quinn does not remake private-sector labor law but does put an end to one of the labor movement’s greatest hopes for expansion: commandeering dues payments by recipients of state subsidies. While the decision may be narrow—the Court, after all, did not rule that no public workers may be forced to support a labor union—its impact will be anything but that.

The Illinois law at issue here in Harris was at the leading edge of a nationwide movement over the past decade to organize home-based care workers, including medical assistants and even family child-care providers, and thereby to “reinvigorate organized labor.”

Though a recent phenomenon, the use of sham employment relationships to support mandatory union representation has spread rapidly across the nation. In just the decade since SEIU waged a “massive campaign to pressure [] policymakers” in Los Angeles to authorize union bargaining for homecare workers, home-based care workers “have become the darlings of the labor movement” and “helped to reinvigorate organized labor.” From around zero a decade ago, now several hundred thousand home workers are covered by collective-bargaining agreements.

This quick growth is the result of a concerted campaign by national unions, particularly SEIU, to boost sagging labor-union membership through the organization of individuals who provide home-based services to Medicaid recipients. Since SEIU’s Los Angeles victory in 1999, labor unions have undertaken successful campaigns to establish nominal employers for homecare workers in Oregon (2000), Washington (2001), Illinois (2003), Michigan (2004), Wisconsin (2005), Iowa (2005), Massachusetts (2006), Missouri (2008), Ohio (2009), Pennsylvania (2010), Connecticut (2011), Maryland (2011). (Three states—Ohio, Pennsylvania, and Wisconsin—subsequently repealed this authority.) As labor law expert Peggie Smith puts it, those campaigns have “been hailed as labor’s biggest victory in over sixty years.”

Nor has this model been limited to homecare providers. Over the past five years, organized labor has directed its efforts to organizing home-based childcare providers, including childcare provided by family members who receive public support or subsidies. By February 2007, seven states had recognized unions as the exclusive representative of home-based child care providers; over the next three years, an additional seven states followed suit.

All this has added up to big money for big labor. Just one of the Illinois programs at issue in Harris involved approximately 20,000 personal assistants who pay SEIU over $3.6 million per year.

Today’s decision will slow, and perhaps eventually end, that flow of funds, as workers decide they can represent their own interests and would prefer to keep their earnings for themselves and their families. So while the Court did not go all the way to striking down compulsory support of public-sector unions—as union supporters feared it would—it does deal a major blow to organized labor where it hurts the most: members and money.