The National Right to Work Legal Defense Foundation filed a lawsuit yesterday challenging a Massachusetts law that provides for the unionization of certain family childcare providers, such as nannies and nurseries. The suit is the latest of several recent challenges the NRTW has brought against state unionization schemes, including an Illinois case, Harris v. Quinn, now pending before the Supreme Court.

The unionization of state employees is an issue of state law, and several states over the past five years have passed legislation expanding the definition of “state employees” to include publicly subsidized workers in nontraditional workplaces, such as home healthcare workers or live-in nannies. Many of these workers receive state vouchers or public payments when they care for low-income families. The purpose of the various state unionization laws is to allow these workers to collectively bargain with the state over voucher rates through unions, rather than require the workers to bargain over rates individually. But to avoid the free-rider problem that might result if a union improved voucher rates for all workers but only received dues from some of them, the state laws contain “union security” or “agency shop” clauses that require all workers in a bargaining unit to pay dues — regardless of whether they wish to join the union.

The Supreme Court upheld this practice in a 1977 case called Abood v. Detroit Board of Public Education, writing that union security clauses are essential for “labor peace.” But recently, in 2012’s Knox v. SEIU, the Court suggested that Abood may not have paid sufficient attention to the First Amendment problem of compelling a worker to pay dues to a particular organization.

The NRTW has taken advantage of Knox‘s suggestion, bringing cases against union security clauses in CaliforniaIllinois, Minnesota, and Texas. Yesterday, the NRTW brought Massachusetts into the picture. In 2012, Massachusetts enacted legislation that defines “public employees” to include family childcare providers — including family childcare homes, relative care providers, and in-home care providers — who receive payment from the state for providing childcare services to low-income and at-risk children. If a majority of family childcare providers in a bargaining unit indicate their support to unionize, the law calls for the state to certify an exclusive representative for all workers in the unit to bargain over training opportunities, recruitment, and the rate structure for payments. The law also authorizes union security clauses. Earlier this year, the state and SEIU Local 509 entered into a collective bargaining agreement that includes such a clause, leading the NRTW to bring its case, D’Agostino v. Patrick.

In substance, the complaint is nearly identical to the case pending before the Supreme Court, Harris v. Quinn, which we have covered extensively on this site. The plaintiffs, individuals who operate childcare businesses in their homes, argue that the Massachusetts law violates their First Amendment right to choose with whom they associate to petition the government for a redress of grievances. Accordingly, the federal district court in Massachusetts will likely wait until after Harris is decided before issuing its own legal conclusions, as other lower courts have done.

Edit (4/17 at 3:48): An earlier version of this post incorrectly suggested that Harris could be dismissed as unripe. While one group of plaintiffs in Harris have not yet been subject to a union security clause, a second group is subject to such a clause and has presented a claim that the Seventh Circuit heard on the merits.