And a newly released Pew Research Center poll finds respondents taking labor's side: 42 percent favor the unions, compared to 31 percent supporting Walker.

That doesn't mean that limiting the public sector's collective-bargaining rights isn't good policy--or good long-term politics, either.

The generous benefits that have been negotiated in the past are unsustainable in the long term, especially with the baby boom generation heading into retirement. Any system where labor unions are effectively negotiating with their allies, at least when labor-backed Democrats are in power, is fundamentally unfair. And collective-bargaining agreements for teachers are filled with the kind of bureaucratic work rules that make firing incompetent teachers all but impossible, offering minimal incentive for excellence.

Even longtime labor leader Andy Stern, the former head of the Service Employees International Union, told The Washington Post that the status quo for unions was unacceptable--and that unions have been too slow to take the lead in advancing reforms to make the movement more relevant.

"The question is whether the public-sector unions can get on the side of innovation and quality," Stern said.

That's the argument Walker could be making in tandem with budget concerns. It's not just about penny-pinching, but about advocating strategies to make government more efficient, effective, and accountable.

Americans care as much about the quality and effectiveness of government services as they do about guaranteeing benefits to government workers. The documentary Waiting for Superman showcased the human cost of rules protecting ineffective teachers in public schools. Ask anyone about their local DMV if you want a ground-level view of government services.

That's the real-life argument Republicans would be wise to embrace as they make the hard sell on fiscal reforms. The public might be prepared for straight talk on entitlements, but it's important to offer reforms--the light at the end of the tunnel--in exchange for austerity. It might take painful cuts at first, but it's in the service of a long-term benefit.

Focusing on the narrower budget implications of restraining collective bargaining, by contrast, is a tougher sell. Taking away collective bargaining, simply put, doesn't come across well to many Americans.

A USA Today/Gallup poll found that 61 percent of national respondents opposed "taking away some collective bargaining rights of most public unions." The Democratic firm Greenberg Quinlan Rosner found 58 percent of Wisconsin voters are opposed to restricting collective bargaining--and 41 percent feel strongly about their opposition.

That doesn't mean it's ultimately a losing issue for the governor. On a complex subject like collective bargaining, where many Americans are just beginning to learn about the issue, the numbers will be volatile. The precise wording of a question--Gallup frames collective bargaining as a "right," for example--can skew the results.