Little-mentioned in coverage of last week's congressional elections was the role played by labor unions in turning out a big vote for the Democrats. According to the AFL-CIO, one in four voters were union members, even though unions make up only 12 percent of the workforce, and three quarters of them voted Democratic.

Unions remain the staunchest allies of the Democratic Party and its biggest source of "volunteers" -- often union members who are on the union payroll while they engage in voter registration and get-out-the-vote efforts. And while there's nothing wrong with unions collecting voluntary political contributions from their members and donating to the candidates of their choice, much of what unions spend on politics is anything but voluntary. Two cases now before the U.S. Supreme Court could change that, Davenport v. Washington Education Association (WEA) and Washington v. WEA.

Voters in Washington state enacted a "paycheck protection" law through popular referendum in 1992, Proposition 134, which forced unions to get permission from their members before any of the dues they paid were spent on politics. The Supreme Court has previously affirmed the right of individuals represented by unions to seek a refund for that portion of their dues that goes to fund political and other non-collective bargaining-related activities, in the cases of Abood v. Detroit Board of Education in 1977 and Communications Workers v. Beck in 1988.

But those decisions, which have never been adequately enforced by the National Labor Relations Board anyway, have been interpreted to require that individuals petition the union annually for the refund, which many are afraid to do. Prop. 134 put the onus where it belongs: on the union to get members to agree that a portion of their dues would go for politics before it was deducted from their paychecks.

But when the state tried to enforce the law, the Washington state Supreme Court threw out the paycheck protection law in a bizarre opinion, claiming it violated the First Amendment rights of the union. Now the state court decision is being appealed by the state and groups representing both union members and nonunion employees.

The National Right to Work Legal Defense Foundation (NRWLDF), which is lead counsel for 4,000 nonunion teachers who are forced by state law to pay WEA dues in order to keep their jobs, hopes that the Supreme Court will not only reverse the state court decision but expand workers' rights. NRWLDF would like to use the case to force unions to rebate to nonmembers all forced dues that go not just to politics but lobbying and organizing activities as well. In addition, they'd like nonmembers to have this right automatically rather than having to apply for the rebate each year.

Stefan Gleason, vice president of the NRWLDF, points out that even if the group wins in the Supreme Court it won't entirely solve the problem. Most states force workers to pay dues, sometimes called agency fees, if a union contract is in place. Only 22 states have right-to-work laws that protect the rights of individuals to choose not to join or pay dues to unions, even when the union is the recognized bargaining agent for the employees. Gleason maintains only a right-to-work law provides real protection, noting that paycheck protection laws are "like trying to recover stolen loot rather than preventing the theft in the first place."

And there is a lot of loot. The AFL-CIO claims it spent $44 million in the 2006 election. The Service Employees International Union spent $65 million. And this money, which comes primarily from dues, is on top of the voluntary money raised by union political action committees, which totaled nearly $200 million for the 2006 elections. In Washington state, for example, the WEA and its national affiliate, the National Education Association, spent $1.8 million, more than any other organization according to an article in the Seattle Post-Intelligencer.

The Supreme Court will hear the Washington cases in January. The outcome will decide whether individual workers' rights trump those of unions. It could also level the playing field in future elections so that unions will have to do what every other group involved in politics does: raise voluntary contributions to support candidates.