Retiring Rep. Lynn Woolsey, D-Petaluma, endorsed Assemblyman Jared Huffman of San Rafael as her successor on Thursday, two days after Huffman scored a big win in the primary election.

Woolsey, who is stepping down after 20 years in office, described Huffman as a "principled progressive and an effective coalition-builder."

"Jared is that rare public servant with both the courage of his convictions and the ability to work constructively to get things done," Woolsey said in a statement from her office in Washington.

"His victory this fall would allow me to leave office knowing that the North Coast is in capable hands, with a representative that truly reflects our district's values," she said.

Huffman, who is termed out of the Assembly this year, finished first with 37.3 percent of the votes in Tuesday's primary election for a North Coast seat in Congress.

Republican Dan Roberts, a political newcomer, came in second to earn a potential spot in a November runoff with Huffman.

Woolsey's endorsement amounts to a symbolic passing of the torch to Huffman, who is considered virtually a sure bet to win in November because of the district's overwhelming Democratic registration. In the primary, almost 75 percent of the votes went to Democrats.

If elected, Huffman would join Rep. Mike Thompson, D-St. Helena, whose district includes Santa Rosa, Rohnert Park and Sonoma, as Sonoma County's representatives in the House of Representatives.

Norman Solomon, a Democratic author and activist from west Marin County, was 1,379 votes behind Roberts with tens of thousands of absentee ballots uncounted in the six-county coastal district stretches from the Golden Gate Bridge to the Oregon border.

Woolsey, 74, said she was endorsing Huffman "regardless of the final vote tally."

Huffman said he had expected an endorsement from Woolsey, whom he described as "a great friend" whose advice he values.

"She's represented the North Bay with such passion and moral clarity for the past 20 years, leaving very big shoes to fill," he said.

Huffman, 48, said Woolsey's endorsement amounts to a call for unity among Democrats heading into the November election in which the party hopes to re-elect President Barack Obama and regain control of the House.

"Democrats need to stand shoulder-to-shoulder this fall," he said.

Huffman said Solomon called to congratulate him Tuesday night, and both Stacey Lawson and Susan Adams, who finished fourth and fifth, respectively, left him similar messages Wednesday.

"That really is a classy move," Huffman said. "It's hard to lose an election."

Solomon's political consultant, Tom Higgins, said Thursday that with at least 40,000 uncounted ballots in the congressional district and a 1.1 percent gap between them, Solomon still could overtake Roberts and face Huffman in November.

Solomon, well known in liberal Democratic circles, had positioned himself as the ideological heir apparent to Woolsey.

Regarding Woolsey's endorsement, Solomon said in an email Thursday: "As I've said repeatedly in recent months, I want to be elected not anointed."

Huffman had collected more than 800 endorsements, including nods from Thompson and Sen. Dianne Feinstein, D-Calif.

Woolsey, in an interview Thursday, said she had pledged from the start not to endorse anyone during the primary campaign.

Of the eight Democratic candidates, she said Huffman, Solomon, Adams and Petaluma Vice Mayor Tiffany Renee had been "wonderful supporters of mine" and it "didn't seem fair" to side with one of them.

Huffman said he became well-acquainted with Woolsey after winning his seat in 2006.

Huffman said he initially intended to serve three terms in the Assembly and step out of politics.

On a visit to her office four years ago, Woolsey surprised him by noting her retirement would come the year he was termed out, Huffman said.

"I knew what a good legislator he was," Woolsey recalled.

Huffman said his wife, Susan, immediately embraced the idea of him taking a job 2,300 miles away.

Her response: "You gotta do it," he said.

You can reach Staff Writer Guy Kovner at 521-5457 or guy.kovner@pressdemocrat.com.