California unions are fighting for their life to defeat a Nov. 6 ballot measure that would choke off their political cash, but in other states where labor has lost similar fights, they haven't just rolled over and died.
Whether through litigation, legislation, ingenuity or some combination of the three, unions elsewhere have adjusted.
"As a general rule, the campaign finance environment is very dynamic," said Ken Mayer, a University of Wisconsin, Madison, professor who studies campaign finance. "Affected groups don't just sit there and say, 'Game over.' They always adapt and continue exercising influence."
Eight states over the last 20 years have put laws on the books to either limit how members' dues can be applied to a union's political activities or require members to give their consent for such uses.
California's Proposition 32 goes further by banning unions and corporations from using any payroll-deducted money for politics. Members who want to donate to their union's political fund would have to write checks or authorize electronic transfers.
Unions have said Proposition 32 is a virtual death sentence for their clout, because, unlike business interests, they use payroll deductions from their members to raise political cash.
A loose alliance of wealthy Republicans, anti-tax activists and Silicon Valley entrepreneurs is backing the measure. Their interests wouldn't be hit as hard as unions' because they draw their funds from individual donors and company resources.
"We haven't seen anything quite like Prop. 32 in any other state," said John Logan, an expert on union legislation and director of labor and employment studies at San Francisco State University. "Depending on what happens in November, we could see this again elsewhere."
Still, when other states have enacted restrictions, unions have adapted.
In Washington, the state with the longest history dealing with payroll deduction restrictions, union donations are five times what they were before voters required union members to give annual consent before their dues could be used for political purposes.
Ohio, Michigan, Alabama and Arizona adopted different versions of a payroll deduction law. All are held up in court following union lawsuits.
In Michigan, a traditionally labor-friendly state, unions have also put up their own ballot measure to overturn a law passed this year that prohibits public schools from automatically deducting union dues from the paychecks of teachers and other employees.
When lawsuits don't work, unions, like other interest groups facing new money rules, have found work-arounds.
Michigan in 1994 also banned unions from using payroll-deducted money for campaign donations to candidates. The unions simply spent the money on their own independent efforts.
"They just put up their own billboards, run their own ads," said James Sherk, a labor economics policy analyst for the conservative Heritage Foundation.
"I've been here since 2000, and no one has ever talked about the 1994 law," said Dale Belman of the Michigan State University School of Human Resources and Labor Relations. "It's really not an issue."
Some state changes have had some impact on unions, however.
Idaho, for example, passed a law in 2003 that banned automatic public union deductions for political activities from a member's paycheck. The law didn't cover private-sector unions.
"It has made it difficult to get contributions," said Penni Cyr, president of the Idaho Education Association.
For years, the union was the perennial top contributor to Idaho politics despite the state's Republican bent, according to the nonpartisan Institute on Money in State Politics based in Helena, Mont. By the time the U.S. Supreme Court in 2008 knocked down union efforts to overturn the law, the association had slipped to fourth place.
The Idaho union now raises political money via members' direct contributions and electronic funds transfers, Cyr said, but those methods are more unpredictable and more costly to the union.
"We're working hard to make it work," Cyr said, "and we're making inroads. Our members do understand the value of donating to the political PACS, and they're warming up to this."
While unions can make changes to comport with new fundraising laws, sometimes they work on changing the law itself.
In Washington, for example, the state teachers union maintained enough clout to successfully lobby lawmakers to change a provision in the 1992 law that mandated members give annual written permission for their dues to be spent on politics.
The 2002 law changed that to a one-time opt-in and written annual reminders from employers of members' right to opt out.
Meanwhile, the union blended its political and non-political money. It spent some $1.6 million the year that voters approved Initiative 134, according to the Montana institute. The contributions accounted for nearly 7 percent of all political spending in 1992.
Washington labor organizations in 2010 chipped in $13 million, about 13 cents of every dollar spent on Washington state politics that year. Even after adjusting for inflation, that's five times the money Washington unions contributed in 1992.
"The law hasn't produced lower union donations to campaigns," said David Nice, who researches state and local politics at Washington State University in Pullman.
Eventually, litigation over how the union mixed dues money reached the U.S. Supreme Court, which in 2007 ruled it had violated a constitutionally sound law.
Although several polls show California voters are leaning against it, union leaders are thinking about their next move should Proposition 32 pass.
They'd certainly sue, a move that could maintain the status quo while lawsuits move through the courts.
"The idea of legal challenges wouldn't surprise me at all," said Dean Vogel, president of the California Teachers Association. "A lot of (legal) questions are going to need to be answered."
They'll also continue to organize and press the labor agenda.
"Should this thing pass, we're still going to do everything we can to continue what we've done in the past," Vogel said. "How effectively we'll be able to do that will be very questionable. Cut off your lifeblood, and you've got a problem."