Local governments with white-majority elected boards throughout California -- from small cities and school districts to hospital and community college districts -- are increasingly facing threats of lawsuits for not reflecting the demographics of their constituents.

While lawyers already have sued Tulare and threatened Visalia with litigation -- both heavily Latino communities with all-white city councils -- many other Central Valley cities and districts could also be vulnerable under the 10-year-old California Voting Rights Act.

"We're seeing the fastest change in how California organizes local government since the Progressives of the early 20th century," said Douglas Johnson of the Rose Institute of State and Local Government at Claremont McKenna College, who has been critical of the law. "The law is extremely expansive. Every local government in California should be looking into this."

Particularly striking against this backdrop are the 14 cities in California where all-white councils preside over communities where either Latinos or Asians make up the majority of residents. They include Tulare and Porterville, while several others are clustered in the Los Angeles area.

Another 20 cities have Latino majorities and only one minority on city council, including Madera and Coalinga.

Such cities can make especially attractive targets for civil rights lawyers, who see the stark disparities as evidence of a systemic problem.

"These are the cities that should recognize that they are low-hanging fruit for groups who might want to bring lawsuits," said Paul Mitchell of Redistricting Partners, a Sacramento-based consulting firm that works with local governments to determine their vulnerability under the law.

The far-reaching law prohibits local governments from holding at-large elections -- in which the entire community votes for a slate of candidates -- if that system weakens the ability of minorities to elect candidates of their choice.

An elected board can be found in violation if voting statistics show the community polarized along racial lines. That happens, for example, when Latinos vote more than their white neighbors for Latino candidates.

Elected boards that violate the act can be forced to divide their communities with district elections, in which different areas elect their own representatives. That way, districts with a high concentration of minorities could more easily elect one of their own.

A series of court victories and settlements has created a ripple effect in which many school districts are switching to district elections voluntarily rather than face expensive lawsuits.

Since 2009, 69 school boards applied with the state Board of Education to make the switch, including 11 from Fresno County.

At the same time, lawyers have ratcheted up their legal threats in the last two years, shooting off letters to cities such as Visalia, Santa Clara, West Covina and Whittier. The Visalia City Council decided Monday to put a change to district elections on the November ballot.

The 2010 suit against Tulare argued that, even though the city then had a Latino council member, he wasn't the "candidate of choice of Latino voters." Tulare settled for $225,000, which went to the plaintiff's lawyers, and will hold a June vote on switching to district elections.

City Council Member David Macedo said he would encourage voters to approve district elections because, given the law, "one way or another, that's the way it's headed."

At-large elections challenged