When a former professional labor organizer, who won county office thanks to union support, helps push through a controversial clampdown on government workers’ benefits, you know the political climate has changed in liberal Montgomery County.

County Council President Valerie Ervin (D-Silver Spring) organized poultry and catfish farm laborers in the Mississippi Delta in the 1980s. She came to Washington to work at the United Food and Commercial Workers headquarters.

Despite that background, she led the council in an overwhelming vote Tuesday to overhaul the county’s disability retirement system over passionate opposition from employees’ unions.

It was only the latest step in a continuing effort by the council and County Executive Ike Leggett (D) to save money in hard times, even at the expense of county unions that have long been kingmakers in Montgomery Democratic politics.

Ervin said she has paid a personal toll in hurt relations with labor officials whom she has long known. One is Gino Renne, president of the county government employees union.

“It’s kind of a heartbreaking scenario for me to be where I am vis-a-vis the people I have known and worked with for many years,” Ervin said.

She made no apologies, saying the unions have been unwilling to bargain realistically, given how county resources have dwindled since the recession.

The unions contend that the council should not interfere in collective bargaining. Ervin said the council stayed out of the disability retirement issue for 21 / 2 years waiting for the unions to budge, but to no avail.

“We’ve given them many chances to negotiate with the executive, and it clearly wasn’t going to happen,” Ervin said.

Ervin and the rest of the political leadership deserve applause for daring to disappoint their former friends. Although it’s regrettable to see working people whacked by a pay freeze, furloughs and reduced benefits, the money is not there to do otherwise. Montgomery has already slashed spending on other worthy recipients, such as libraries, parks and recreation programs.

Ervin’s shift in perspective illustrates an important realignment in Montgomery, the Washington region’s second largest jurisdiction.

Even though Montgomery is hardly a working-class county, unions have played an out-sized role in politics. That’s partly because they’re openhanded with campaign contributions and campaign workers. Ervin said union “boots on the street” were crucial to her successful first campaign for the council in 2006. (She was reelected last year.)

Union opposition played a leading role last year in ousting council member Duchy Trachtenberg after she pushed for changes in the retirement system similar to what the council just approved on a 7 to 1 vote (with one abstention).

Unions are also influential because many Montgomery residents, despite being upper-middle-class themselves, instinctively sympathize with working-class people.

Call it empathy for the underdog. Call it liberal guilt. Either way, lawyers and senior lobbyists earning well into six figures feel righteous voting for candidates whose campaign literature boasts union endorsements.

In past years, such sentiment translated into routine support for union objectives. Politicians okayed generous pay increases. They looked the other way when police officers retired on tax-free, full disability even for only a partial incapacity like a bad knee.

Now, by contrast, county employees didn’t get a raise in the budget year that ends Thursday. They aren’t going to get one in the year beginning Friday. The new, two-tier disability plan will pay less to workers who retire when only partially debilitated. The council passed legislation in December to give management more leverage in arbitration.

“What’s happening is we are in a different environment altogether,” Ervin said. “We don’t have the revenue coming into the county that was coming in years ago.”

Although it hasn’t been easy for her effectively siding with management, she draws a distinction between the chicken plant workers whom she once represented and the public employees with whom she’s wrestling today.

“In my opinion, they’re very different, because taxpayers are the ones who are responsible for paying the freight,” Ervin said.

I discuss local issues at 8:51 a.m. Friday on WAMU (88.5 FM).