One of the most vexing disputes over district elections focuses on the level of risk facing Santa Rosa for being sued under the California Voting Rights Act for having "racially polarized voting."

The law, passed in 2001, made it easier for minority groups to prove their votes were being overwhelmed by those of white voters. Several communities have since been sued, including Hanford, Modesto and Madera, in some cases resulting in the cities paying millions in legal fees and being required to switch to district elections.

"We're seeing these sweep the state," said Douglas Johnson, president of National Demographics Corporation.

Supporters of Measure Q on the Nov. 6 ballot say that instead of waiting to be sued, the city should switch to district elections now, which would protect it from such action.

"My opinion is there is a real vulnerability to the city," said former Sonoma County Counsel Steven Woodside, who lives in Fountaingrove.

The fact that so few Latinos have been elected to public office in the city (Ernesto Olivares became the first Latino council member in 2008) and that higher concentrations of Latinos live on the city's west side would likely make it easier for attorneys to make their case, Woodside said.

Also given demographic trends, it is clear Latinos will continue to make up a larger percentage of the population, he said.

"This is, in my view, inevitable, so why not take care of it now?" Woodside said.

But Herb Williams, the political consultant helping direct the Measure Q opposition, is among those who call this a "scare tactic." They say there is no evidence of racially polarized voting in the city.

Determining whether such a pattern exists is complicated, and to date no one has attempted it in Santa Rosa, said attorney and Santa Rosa Schools board member Bill Carle.

Experts would need to do a complex analysis comparing voting patterns with demographic data to determine whether the pattern exists. Absent that, no one can say for sure, he said.

"There is no evidence that would suggest that we are in danger of being sued, just like there is no evidence that we are clean of racially polarized voting," Carle said.

Nor is there any suggestion that the city is being considered as a target for a suit in the near future, largely because there are other communities with greater histories of racial imbalances, Johnson said.

"Santa Rosa is not on anyone's bright-red target list," he said.

Williams said he supported putting district elections on the ballot even though he opposes them in practice because he believes if voters were given the chance to weigh in on the subject, the legal risk to the city would be lessened even if district elections are rejected.

"That's exactly the opposite of reality," Johnson said.

Putting district elections to a vote is "dangerous" because if Latinos vote for it and the whites vote it down, that provides evidence of a problem.

"Allowing the majority to show its prejudice by voting against what the Latinos want does not help your defense," Johnson said.

You can reach Staff Writer Kevin McCallum at 521-5207 or OnTwitter @citybeater