Incumbent Efren Carrillo held on to his seat in the 5th District Board of Supervisors race, avoiding a runoff election by taking a final 59 percent of the vote.
Carrillo had a commanding lead from the start over his challengers and held it throughout the long, slow count late into the night.
Former supervisor Ernie Carpenter came in second place, with 28 percent. The third candidate in the race, former Santa Rosa City Councilwoman Veronica Jacobi, received 13 percent.
"I am humbled and excited to continue working on the issues facing the county," Carrillo said late Tuesday.
As precincts started coming in, Carpenter's tally began increasing only slightly.
"That's a good trend but it may not be good enough," said Carpenter.
The candidate who receives 50 percent of the vote, plus one, takes the race. If no candidate had crossed that threshold, the top two vote-getters would have faced off in November.
The vast 5th District, which runs from the west side of Santa Rosa to the coast and up to the Mendocino County line, has long been considered a haven for environmentally-conscious voters. Carpenter represented the district from 1980 to 1996.
But Carrillo, who finished first in an eight-candidate primary at age 27 in 2008, has worked tirelessly for the last 3 1/2 years reaching out to voters in the district. During that time, Carrillo has been able to shore up his base, claiming many voters who did not support him in 2008, including Latino and labor groups.
Carrillo's fundraising machine dwarfed all others in county races, an advantage that allowed him to deliver his message to voters' mailboxes, phones, roadways and radio waves. Carrillo has raised more than $103,000 since mid-March, including late contributions.
It was widely thought that Carpenter's surprise bid to reclaim the seat he held for 16 years before retiring in 1997 would deny Carrillo an easy win Tuesday. Before Carpenter's entry into the race in March, Jacobi, a one-term councilwoman who has now run unsuccessfully for county office three times, was given little chance against Carrillo.
Carpenter, 69, lives in Sebastopol, while Carrillo lives in west Santa Rosa. After the 2010 Census, redistricting added more urban and Latino residents from west Santa Rosa — changes that likely played in Carrillo's favor.
Both Carrillo's challengers sought to build on concerns raised by environmental and progressive interests that have long defined politics in west Sonoma County.
Opponents spotlighted Carrillo's votes in favor of several controversial land-use projects, including the disputed Dutra Materials asphalt plant outside Petaluma and the Best Family Winery project outside Graton. Carrillo's critics said the projects violate approved plans for how the county governs development.
Carrillo, in response, said his votes balanced economic growth with environmental protection.
Carrillo fought hard to avoid a runoff, making countless appearances at festivals and events throughout the spring. But Carpenter, as well as Jacobi, matched his enthusiasm and energy.
"I admire how hard Ernie has worked," Carrillo said.
On Tuesday, Carrillo spent much of the day standing on busy street corners, holding one of his familiar election signs. Drivers honked their horns as they drove by, many of them giving Carrillo a thumbs up.
"I voted for you," said a woman in a van as she up held her "I voted" sticker.