COSTA MESA A power shift on the City Council will take hold Tuesday, when the winners of three open seats take their place on the dais.

The reelection of Councilwoman Sandra Genis and the addition of John Stephens – both aligned with Councilwoman Katrina Foley – will end the voting majority held by council members Jim Righeimer and outgoing members Steve Mensinger and Gary Monahan.

The third seat will be filled by former state Assemblyman Allan Mansoor, who served on the Costa Mesa council from 2002-10.

Mensinger, who was chosen as mayor last year, was denied a second four-year term after being appointed to the council in 2011. Monahan was termed out from running for reelection.

For more than five years, the three-man voting block dominated the council, focusing on outsourcing city services and leaving full-time positions vacant to cut costs, and reviewing large-scale developments, sometimes catching the ire of opponents in the process.

Mansoor, a Mensinger political ally, said that despite the new majority, he “plans to focus on things that can be done, but if I think an issue has merit I will bring it forward regardless of the outcome.”

Stephens said one of his priorities is rebuilding the city’s short-staffed police force and applying greater scrutiny to large residential projects.

“We’re going to be dealing with high-density development in a different way than the prior council,” he said.

Stephens, along with Genis and Foley, supported the voter-approved Measure Y, which requires public voter approval for developments that would that require General Plan amendments or zoning changes, among other criteria. Mensinger, Righeimer and Monahan backed a failed competing measure.

One of the biggest criticisms of the council was the perceived deterioration of civil discourse between the members themselves and the public.

“There have been a lot of personal attacks and name calling from members of the public,” Mansoor said. “They may have a right to say whatever they want but it is very disrespectful and makes a mockery of our city process when adults resort to name calling.”

Aside from being on opposite ends of several issues with Genis and Foley, Mensinger and Righeimer most notably clashed with the city’s police and fire unions during tense labor negotiations.

Both men were outspoken critics of public unions and the influence they wield with government agencies.

Incidents related to talks with the Costa Mesa Police Association resulted in a private detective hired by a now-defunt union law firm pleading guilty in September to attempting to set Righeimer up for a DUI and using GPS device to tail Mensinger.

The union has denied knowing about the illegal actions.

Righeimer said the issue was always about money and not civility, citing the backing of Genis and Stephens by the Costa Mesa Firefighter Association.

“They got the city council they want and it will be very civil going forward,” Righeimer said. “This is how this works and it will switch the other way again.”

Genis said part of why some residents feel displeasure with the current council stems from feeling chastised and not being heard.

“Even before I was elected, watching from the audience, some of the council members seemed to treat others who were in the minority very rudely,” Genis said. “However, I have no desire to retaliate, now that the majority has shifted. I do hope everyone will behave with proper decorum.”

Stephens echoed her thoughts, saying he anticipates greater collaboration between council members regardless of where they stand on the issues.

“I think you’re going to see a lot less 3-2 votes,” he said.

Contact the writer: 714-796-2478 or lcasiano@scng.com