Updated

Dr. Monica Wehby emerged victorious in the Oregon GOP Senate primary Tuesday to take on Democratic Sen. Jeff Merkley in November in a race Republicans hope could help them take back the Senate.

Wehby beat Oregon state Rep. Jason Congers and three other candidates with 51 percent of the vote. Congers placed a distant second with 36 percent.

Republicans are looking to Wehby, a pediatric neurosurgeon and political newcomer, to pull off an against-the-odds victory in territory where a Republican has not won a statewide election since 2002. However, some believe that first-term incumbent Merkley is vulnerable because he has enthusiastically supported ObamaCare.

The health care reform law is deeply unpopular in Oregon because the state’s exchange has been a disaster. The state abandoned its plans for an independent online exchange after it failed to launch and Cover Oregon and its independent contractor, Oracle Corp., couldn't fix it.

Oregon then decided to switch to the federal portal, the first state to do so. On Tuesday, federal prosecutors subpoenaed state records for a grand jury investigation into what went wrong with the website.

Wehby, who has 30 years of medical experience, was an early critic of ObamaCare.  She was on the board of the American Medical Association and was featured in a 2009 ad opposing the Affordable Care Act.

This early opposition to the law helped Wehby gain attention and support from influential Republicans nationally, and she has been endorsed by GOP heavyweights like Mitt Romney, Newt Gingrich and Dr. Ben Carson.

Her challenger Conger raised far less money but was backed by influential social conservatives and groups, including former senator and GOP presidential candidate Rick Santorum.

Wehby might carry some baggage into the general election. Late in the race, police reports surfaced showing that two of her former companions, an ex-husband and a former boyfriend, called police as their relationships were deteriorating and said Wehby had harassed them. The boyfriend, timber-company executive Andrew Miller, later helped fund a super PAC attacking Conger. He said his accusations to police were exaggerated, and he regretted them.

No charges were filed in either incident.

Wehby says the reports have nothing to do with her campaign and are being used as a "political weapon."

Speaking to supporters Tuesday night, Wehby said everyone makes mistakes, but like a lot of Oregonians she's a working mother, balancing a career with raising children.

"I do have a message for those national Democrats who are willing to shred my family for their own political gain: People are tired of your dirty tricks," Wehby said. "We all know that the best way to defeat a bully is to stand up to him, and that is exactly what we are going to do."

Wehby, 51, has kept her focus on the general election, portraying herself as a political outsider. She largely ignored her Republican rivals and instead attacked "Obamacare" and Sen. Jeff Merkley. She's staked out moderate positions on social issues -- she says the federal government shouldn't get involved in abortion or gay marriage -- and says her background as a doctor gives her the expertise to fight the federal health care law.

Wehby will face an uphill climb against Merkley, a first-term Democrat who narrowly defeated a Republican incumbent in 2008. The Democratic Party has an 8-point edge in voter registration and Republicans have struggled for two decades to win statewide elections. While strong in rural areas, the GOP gets hammered in liberal Portland and has watched its influence erode in the city's suburbs in recent years.

If Republicans can put Merkley's seat into play, however, it would boost their efforts to rack up a net gain of six seats and reclaim control of the Senate.

"There's a clear choice in the race for Senate between Monica Wehby, who will vote with national Republicans against Oregon's priorities, and Jeff Merkley, who fights for Oregon and puts Oregon first," Merkley campaign manager Alex Youn said in a statement.

Conger, 45, ran to Wehby's right. He said her stands on social issues are out of step with the Republican Party and pitched his experience winning elections in a Democratic district.

Conger emphasized his biography, overcoming a hardscrabble childhood to graduate from law school. "From homeless to Harvard," read the slogan on his campaign literature.

Big donors were key players in the race, nearly matching the candidates' own spending with about $1 million in independent expenditures. Three super PACs and a traditional political action committee paid for television, radio and Internet advertisements, as well as mail and billboards, supporting both Wehby and Conger.

Also in the race were Mark Callahan, a Salem information-technology consultant; Tim Crowley, a Portland lawyer; and Joe Rae Perkins, a former financial planner from Albany.

Fox News' Dan Springer and The Associated Press contributed to this report