Democrats retained control of a left-leaning Northern California congressional district Tuesday, electing a career politician who said he will side faithfully with the Obama administration on health care, climate legislation and other hot-button policies.

Lt. Gov. John Garamendi used the name recognition he achieved during a 35-year political career in California to steam past Republican David Harmer, an attorney. Garamendi's victory was all but certain after he won the September primary election because the 10th Congressional District is so heavily Democratic, with the party enjoying an 18 percentage point registration edge over Republicans.

That was part of the reason the California special election lacked the flair of another House race Tuesday in upstate New York, where conservatives were trying to make it a referendum on the Obama administration.

With 50 percent of precincts reporting, Garamendi had 55 percent of the vote compared to Harmer's 40 percent.

Garamendi, 64, had said throughout the campaign that he will support the president in his effort to repair the economy and would vote with House Speaker Nancy Pelosi, D-Calif., on health care legislation. He told supporters gathered at his campaign headquarters in Walnut Creek that he planned to be on a flight Wednesday to Washington for his swearing-in this week.

He made clear he would serve the needs of his constituents.

"It's a great night. We have work to do in this district. We're going to deal with the health care issue, the economy, the foreclosure issue, the jobs," Garamendi said. "We're going to start it off in a big hurry."

Garamendi's elevation to the congressional seat marks the latest turn in a political career that stretches back to the mid-1970s, when he was elected to the Legislature. He also has served as California's insurance commissioner, had two failed bids for the Democratic nomination for governor and served as undersecretary of the Interior Department in the Clinton administration.

A rancher with a Harvard MBA, Garamendi spent the weeks leading up to the special general election campaigning against Harmer, who tried to appeal to moderate Democrats and independents with an agenda based on fighting excessive government spending. Harmer, 47, held telephone town halls late into Tuesday in an attempt to court undecided voters.

But a Harmer upset was always a long shot in a district that overwhelmingly favored Barack Obama in last year's presidential race. The seat opened earlier this year when the incumbent, former Rep. Ellen Tauscher, was confirmed to an undersecretary position in the State Department. A call to Harmer was not immediately returned.

The district stretches from the suburbs of the eastern San Francisco Bay area to the edge of the state capital. It includes parts of Alameda, Solano and Sacramento counties.

Garamendi spent Election Day greeting supporters at a union office and a coffee shop in his final push to get voters to the polls. He could not vote in the election because he lives just outside the district but planned to watch returns with family, friends and volunteers at his campaign headquarters.

Candidates are not required to live within a particular district to run for a congressional seat.

Garamendi's departure from the lieutenant governor's post leaves room for political maneuvering within the state. His victory allows Republican Gov. Arnold Schwarzenegger to nominate a replacement to fill the remainder of his term, which runs through January 2011.

California Republican Party Chairman Ron Nehring said the GOP now has an opportunity to pick up a statewide seat.

Either the Assembly or the Senate, both with Democratic majorities, could vote to reject the nominee on a majority vote.