By David G. Savage

The Supreme Court said Tuesday it would hear a major challenge to California's public unions and decide whether they may charge fees to non-members to support collective bargaining.

At issue is a 1970s-era court precedent that allows these unions in California and 20 other states to collect "fair share" fees from all employees.

The court's conservatives, led by Justice Samuel A. Alito Jr., have signaled they see these forced fees as unconstitutional because they require some employees to support a cause they oppose.

In the fall, the justices will hear a direct challenge to the fees brought on behalf of Rebecca Friedrichs, a public school teacher in Orange County who objects to supporting the California Teachers Association.

The case is likely to be seen as crucial test of public employee unions, which have under political attack in several Republican-led states. The outcome may well have a political impact as well, because these unions have been reliable supporters of the Democratic Party.

The Center for Individual Rights, a small conservative group in Washington, wanted to bring the issue before the high court as soon as possible. The group funded the lawsuit, which alleges that forcing Friedrichs and other teachers to fund their union is a type of unconstitutional compelled speech.

The lawsuit said full dues for teachers who join the union are about $1,000 a year, but non-members still have to pay about $650 on average for their share of the cost of collective bargaining, which has been deemed to benefit all workers, including non-members.

Lawyers for the CTA and California Attorney General Kamala Harris defended the union fees on the grounds that they were authorized by law and were a fair way to have all the employees pay the cost of collective bargaining. A federal judge and the U.S. 9th Circuit Court of Appeals rejected the challenge, citing the Supreme Court's 1977 ruling in Abood vs. Detroit Board of Education.

Earlier this year, the conservative group filed an appeal urging the justices to overrule that high-court precedent and strike down what it called the "multi-hundred-million dollar regime of compelled speech."