A tearful state Sen. Pat Wiggins told supporters Sunday that she will not seek another four-year term in the Legislature next year.

"The best decision, at this time, is that I will not be seeking re-election in 2010," Wiggins said Sunday at a campaign fund-raiser at the Kendall-Jackson Wine Center outside Santa Rosa.

Speculation about Wiggins' health and political future had intensified in recent months amid outbursts, odd displays of affection and the 69-year-old senator's apparent inability at times to focus or remember things.

In making her announcement, Wiggins acknowledged she had faced physical disabilities throughout her career. But she did not specifically address why she was not seeking another term, and she and her staff declined comment Sunday.

Just last week, Wiggins said she was running for re-election in 2010 during a brief interview in a hallway at the state Capitol.

On Sunday, Wiggins did not say why she had changed her mind with more than a full year left in her term. She disclosed the decision at what was billed as a fund-raiser for her re-election campaign. Supporters were asked to donate $35 to $3,600 to attend.

Wiggins told the about 70 people in attendance that she had been proud to represent her district, which spans six counties on the North Coast.

"It's a pleasure to represent you, the greatest district in California," Wiggins said, breaking into tears as she concluded her speech.

Tony Alvernaz, president of Santa Rosa City Employees Association, expressed sadness at the announcement.

"It is unfortunate it has come to this. She has done a phenomenal job," he said. "She has carried so much legislation for the working class people of her district."

Wiggins received praise from her colleagues Sunday.

"Senator Wiggins is a great leader and accomplished legislator," said Sen. Mark Leno, D-San Francisco. "All of us who love her offer her and her family our full support and appreciation."

Assemblywoman Noreen Evans, D-Santa Rosa, a close political ally of Wiggins and a longtime friend, will likely run for the Senate seat in 2010, Evans spokesman Terry Price said.

Roseland School District trustee David Rosas has already filed papers to run in the Democratic primary for the 2nd Senate District, which covers Humboldt, Lake, Mendocino, Napa, Solano & Sonoma counties.

Wiggins, a former computer systems analyst who was first elected to the Santa Rosa City Council in 1994. She established herself in the "smart growth" movement and helped strengthen local laws that restrict growth to within a defined city area.

She would rise to become a powerful force in North Coast politics, amassing a sizeable campaign war chest and helping like-minded politicians get into office.

"She has been the core of many of the progressive movements on the North Coast," Price said.

Wiggins was elected to the state Assembly in 1998, representing Napa, Solano and Sonoma counties until she was forced out of office by term limits in 2004. Two years later, she won election to the state Senate, where she compiled one of the best attendance records of any senator, according to state records.

"This is a job she was born to do," said Marty Roberts, who helped Wiggins get elected to the City Council and remains a close friend. "She's been so dedicated to it. She works from her heart."

In 2008, legislators approved 24 of Wiggins' bills, and Gov. Arnold Schwarzenegger signed 17 of them into law — the most of any legislator.

But privately, numerous public officials said they believed Wiggins may be losing her mental grip. Her behavior gained widespread attention in August 2008 during a committee hearing on global warning when she castigated Pastor Robert Jones of Sacramento's Oak Park United Methodist Church.

As Jones was giving his introductory remarks, Wiggins interrupted the pastor to tell him his testimony was "bull----." In a subsequent interview at her Capitol office, Wiggins was unable to articulate why the pastor's comments were so offensive to her.

For months, Wiggins' staff denied there was anything amiss with the senator other than her well-documented problems with hearing loss, which require her to wear special equipment during Senate floor debates or hearings.

Last week, her press secretary, David Miller, issued a statement saying Wiggins "does not have a medical condition which impairs her ability to serve as the senator for the 2nd District."

Sonoma County Supervisor Shirlee Zane and others at the event said they did not know in advance that Wiggins planned to make the announcement, but few seemed surprised and her supporters embraced the decision.

"I think it's the best thing for her and her family," Roberts said. "She's had a wonderful, strong career."

Wiggins' husband, Guy Conner, opened the fund-raising event with an emotional speech that looked back over Wiggins political career. She held on to his arm as he spoke.

After announcing she would not seek re-election near the end of the two-hour event, Wiggins said money from Sunday's fund-raiser would be used to support many of the causes she has long championed, such as the environment and agriculture.

"I'm going to miss having Pat as a colleague," said Assemblyman Jared Huffman, D-San Rafael, whose district includes southern Sonoma County. "I think she has done some terrific things for the people of Sonoma County and she leaves big shoes to fill."

Staff Writer Derek Moore contributed to this story.