The Service Employees International Union and its affiliated local unions have more than 15,000 local members and a history of aggressively backing chosen candidates with both money and campaign workers.

Critics say that influence, combined with what experts say could be voter turnout as low as 25% to 30%, could let the union shape the future of Fresno in a way no union has done before.

"SEIU is the monster in this race," said Michael Der Manouel Jr., a local business owner and Republican political strategist. "They have unlimited resources, paid walkers and a very single-minded purpose."

Union leaders called those statements overblown, saying their members are trying to improve the community, not control it.

"The larger community really values the perspective of our members," said Charlie Eaton, a political coordinator for SEIU-United Health Workers. "The nurses, teachers and thousands of health-care workers who have joined SEIU are valuable members of this community."

Fresno County Supervisor Susan Anderson, who won the union's endorsement for the District 2 race, said she's been criticized for her ties to unions such as SEIU, but she has no qualms about accepting the help of workers in her election. She's accepted more than $7,000 in monetary and nonfinancial contributions from the union so far.

"I've always had very diverse support," Anderson said. "Both from labor and business. The reality is that in Fresno County the most money comes from developers and unions. That's life."

Activity not illegal

It's not new, or illegal, for unions to take active roles in elections. Tim Hodson, director of the Center for California Studies at California State University, Sacramento, said that what makes SEIU different is that its membership has stayed strong even as other unions have declined. The union, which has 1.3 million members worldwide, has been an active force in local races around the country, Hodson said.

The union represents county workers, nurses, teachers and other service-related employees.

"They represent growing areas of the labor market," Hodson said.

"That in turn has helped their influence grow along with their membership."

Hodson said that while union influence has never been as great as opponents have sometimes portrayed, large unions do have the power to influence elections.

"The greatest thing unions can do, in addition to money, is put boots on the ground," Hodson said. "Those workers, whether they are knocking on doors, or working phone banks, can really give a candidate an advantage."

Low turnout boosts union

The influence of the union members could be especially strong in June.

Fresno County Clerk Victor Salazar said the off-cycle primary election June 3 may draw fewer than 100,000 voters countywide. That is well short of the more than 176,000 voters who cast ballots in the February presidential primary, a turnout of 50%.

June's anticipated low turnout will make every vote even more important, Salazar said. That's especially true in the Fresno mayor's race, where the votes will be spread among 11 candidates, and no one is expected to win outright. Only the top two vote getters will continue past the primary.

How SEIU may use that to its advantage is what worries opponents such as Der Manouel. He said SEIU, which asks candidates seeking its endorsement to fill out a questionnaire, uses a pledge attached to the questionnaire as a tool to shape public policy.

The pledge asks candidates to publicly support and actively encourage workers who are organizing unions, and to say that no public money will be used to interfere with striking workers.

The union also has a history of dumping large amounts of money into races, especially in the last few weeks of the campaign.

In 2002, an SEIU-backed political action committee spent more than $225,000 in an attempt to elect former City Council Member Dan Ronquillo to the Fresno County Board of Supervisors. A third of that money came in the last days before the election, including more than $70,000 in late October 2002. In the end, Ronquillo lost.

But the union had better success in 2006.

It spent $216,000 to unseat incumbents and help elect a slate of candidates to the Fresno Unified school board, including tens of thousands of dollars worth of mailers in the days before the election.

Patricia Barr, one of the incumbents targeted by SEIU, called the union's leaders mean-spirited and accused them of stretching the truth.

The mailers, Barr said, blamed her for board actions that happened before she was elected. She lost the race.

"The leadership is very ruthless and unbelievably brazen in what they do," Barr said. "I understand the role of a union, but there's a need for more collaborative unions instead of these mean-mouthed ones."

Union to take active role

Now SEIU is poised to take an active role in the June primary for races at both the city and county level. The union has endorsed Henry T. Perea in the mayor's race and Anderson in the race for Fresno County's second supervisorial district.

The union has not taken a stance in Fresno County's fifth supervisorial district race, or announced endorsements for the City Council races.

Accepting the support of a union such as SEIU comes with advantages and challenges, said Tom Holyoke, an assistant professor of political science at California State University, Fresno.

"It's a difficult choice that a candidate needs to make," Holyoke said.

"It can mean tremendous support, but there is also the question about what you will be asked to do in return."

Der Manouel said he has no doubts what candidates are asked to do for SEIU, especially considering the pledge.

Eaton said critics misunderstand the candidate pledge.

"Our membership invited many candidates in all of the races to seek endorsements from us," Eaton said. "We talk to, and interview, everyone who chooses to come in. We decide who to support based on who will be the best candidate, not based on who signs the pledge."

John Hutson, a leader with the International Brotherhood of Electrical Workers local 100, said he's been uncomfortable at times with the approach SEIU uses to choose candidates.

"To ask someone to be on their side on every issue isn't good for the community," Hutson said.

"If it's not good for the community, it probably is not good for our members either."

Eaton doesn't dispute the influence SEIU could have on the election. He said the workers SEIU represents -- nurses, government workers, teachers and others -- are prominent members of the community, and will share their opinions of candidates with their co-workers and neighbors. They also will share money to help get those candidates elected.

"I don't know how much resources our members will use to talk about candidates," Eaton said. "But in this election, our members, as in every election, have plans to talk about who they think should be elected."