Republican surgeon and lawmaker Knute Buehler is running run for governor in 2018, fighting the tide of history and a Democratic voter edge in an effort to reclaim the top state post for his party.

Buehler, who represents Bend in the Oregon House and is viewed as a moderate in his party, had been widely expected to run against Gov. Kate Brown. He could well be her most serious challenger if the governor decides to seek reelection next year.

A Republican has not occupied the governor's mansion since 1987, however, and Democrats hold a significant advantage in registered voters. Republican ex-Blazer Chris Dudley, who came within a percentage point of beating John Kitzhaber in 2010, had name recognition beyond many politicians' dreams.

"The biggest issue is people simply do not know who (Buehler) is," said Jim Moore, director of the Tom McCall Center for Policy Innovation at Pacific University. "

Brown, 57, has been fundraising and campaigning since the day after she was elected last year, but she has yet to formally announce her plans. She already has a formidable fundraising advantage on Buehler, with $1.3 million in the bank even after spending more than $700,000 this year. Buehler's campaign had just $128,000 as of Thursday and reported spending $107,000.

Buehler, 53, declined a request for an interview Thursday. In a campaign email, he wrote that he is running to "reform Oregon's struggling public schools," improve the state's budget and boost Oregon's middle class.

Buehler, who opposed a bill this year that would have scaled back a business tax break that critics said is helping wealthy doctors and lawyers, said his budget strategy would rely on spending controls. To help the economy, he proposed additional career training and "resisting excessive, job-killing regulations." The lawmaker made his initial announcement in a meeting with the editorial board of his hometown newspaper, The Bulletin, Wednesday.

"Kate Brown has had her chance and she's failed," Buehler wrote. "She's refused to lead on essential budget, pension and education reforms critical to Oregon's future. Instead, she simply demands higher and higher taxes."

Brown's campaign manager, Thomas Wheatley, declined to comment. But Jeanne Atkins, chair of the Democratic Party of Oregon, said in a statement that "Governor Kate Brown beat (Buehler) before and she will beat him again."

In 2012, Brown and Buehler both ran for secretary of state. Brown won that election by 8 percentage points, and was elevated to governor in February 2015 when then-Gov. John Kitzhaber resigned amid an influence peddling scandal.

Atkins, who stepped in as secretary of state after Brown appointed her, said Buehler's "shady business dealings will make it a hard campaign for him."

The Democratic Party of Oregon filed an ethics complaint against Buehler earlier this year, alleging that he failed to disclose payments from medical device maker Stryker Corporation and pharmaceutical company Pfizer. Oregon ethics officials ultimately determined Buehler had largely met state requirements for public officials to disclose the sources of their incomes, because the payments went to a company Buehler owns and he disclosed his income from that company.

The Oregon Government Ethics Commission found, however, that Buehler failed to disclose $12,500 in payments he received in 2013 for serving on the board of a Bend hospital and issued a letter of education last month.

Buehler has been building his credentials as a moderate Republican. He pushed successfully in 2015 to expand access to birth control -- a cause also important to Brown -- and voted last year to pass an anti-coal bill that doubled the state's renewable energy requirements. Many Republicans strongly opposed that bill.

This year, Buehler opposed a plan to enact rent control and voted against a bill that would have allowed municipalities to adopt their own rent limits. That bill died in the state Senate. Although Buehler did not explain his "no" vote on the bill in April, he did discuss his skepticism of regulating rents at a committee hearing in late 2016.

"I am skeptical that there's anyone who's so smart they can determine the right return on equity, who can determine the right mix of housing, who can determine who should actually benefit from that rent stabilization," Buehler said.

Buehler also voted "no" on a $550 million tax plan to fund Oregon's Medicaid program, which was a top priority for Brown.

He co-sponsored a bill with Portland Democrat Sen. Elizabeth Steiner Hayward that would have created a suicide prevention program to educate gun dealers and buyers. The proposal had support from the Association of Oregon Community Mental Health Programs, League of Women Voters and a group called Gun Owners for Responsible Ownership. However, the bill drew opposition from the National Rifle Association and Democratic leaders allowed it to die in committee.

So far, at least one other Republican appears to be pondering a run for governor. Happy Valley Mayor Lori Chavez-DeRemer created a political action committee in late June to explore running for governor. She did not return a call for comment on Thursday.

-- Hillary Borrud

503-294-4034; @hborrud