Pamela Harris is an Illinois homemaker who takes care of her developmentally disabled son, Joshua. She gets financial help from a state program funded through Medicaid.

Technically, the subsidy goes to Joshua, who "employs" his mother as a home health care worker. Because of this arrangement, Illinois has decided that not only is she a state employee, but that it has compelling interest that she join a union.

Harris still doesn’t know why. It is not like she ever plans to go on strike against her son.

"I kept asking, 'What’s the benefit to me?' I could never get an answer," she told me Monday.

On Jan. 21, the U.S. Supreme Court will hear arguments by lawyers for her and seven other women, all but one of whom look after family members, into whether Illinois' push to unionize them is constitutional.

There’s a good chance that the justices will go further and upend existing precedents on public sector unions. The whole practice of requiring government employees to support a union could be ended.

Justice Samuel Alito’s majority opinion in last year’s case, Knox v. SEIU, hinted at it. He said that compulsory union fees "constitute a form of compelled speech and association that imposes a significant impingement on First Amendment rights."

Illinois’s policy, critics contend, does just that. The providers may be paid by the state, but they work at home, usually their own home. Their employment is based on arrangements with the patients — who can fire them if they want.

Yet in 2003, then-Gov. Rod Blagojevich declared that home workers for the physically disabled were now state employees. Anyone who does this work now has to join the Service Employees International Union, or at least pay it monthly fees.

I wanted to ask Blagojevich about this decision but was prevented by the fact that he is currently serving a 14-year sentence in federal prison on 17 counts of corruption related to his duties as governor.

In 2009, current Gov. Pat Quinn declared home workers for the mentally disabled were also state workers.

Tellingly, both declarations stated that they were not public employees for the purposes of state pensions, health benefits or protection from civil liability. Just unionization.

Harris found herself in the position of potentially having to pay monthly fees to a union to negotiate with the state on how she cares for Joshua.

"My primary concern is that someone else will be telling me how to best care for my son," she said, adding that that’s money she could be using to care for her son.

A union does not currently represent workers for the mentally disabled but that’s mainly because two different ones, SEIU and the American Federation of State, County and Municipal Workers, are fighting over the contract. Both lost an October 2009 write-in election.

But it could still happen. There’s no sunset on Quinn’s order and a union only needs to get 51 percent of the workers to sign up to force the rest to get onboard. They can keep trying until they get it.

Union organizers first approached Harris when they knocked on her front door. The state had given away her contact information without her knowledge.

“They said they could get me extra money, but I know the program is capped,” Harris said. The organizers have been back twice. She then reached out to the nonprofit National Right to Work Legal Defense Foundation, which is legally representing her.

It is always hard to predict what the Supreme Court will do. Observers might be reading too much into Knox. The justices could limit their ruling to whether the plaintiffs really are state workers.

Harris said she’s just glad to be heard.

"A mom in Illinois raised her hand and said, 'This isn’t right.' Now the Supreme Court will listen," she marveled. "The system really does work."