Oregon Sen. Jeff Merkley really did not want to run against Monica Wehby.

She had the résumé of a formidable challenger: a pediatric neurosurgeon, a pro-choice mom in socially liberal Oregon, and a Republican woman to rebut the Democratic talking point about a GOP “war on women.” The subject of a friendly front-page New York Times profile in March, she went on to attract accolades from Mitt Romney and national Republicans, and outside money from conservative entities like the Koch brothers.

Another reason the first-term senator was concerned: his favorable ratings were hardly stellar.

“He polls like a generic Democrat. There’s no great groundswell that Merkley is a great guy and we should reelect him,” said Jim Moore, a professor of political science at Pacific University. “With a weakness like that, Wehby on paper looks like she should be a great challenger.”

Democratic operatives set out to tarnish her in the primary in the hope that Republican voters would instead nominate a far-right candidate. They failed.

And yet, in a stroke of luck, Wehby turned out to be a dream opponent for Merkley anyway. Her campaign has — slowly and painfully — self-destructed due to scandals and stumbles, making the once-concerning Oregon race a rare bright spot in a slog of an election year for Democrats. Eleven days away, she’s down 21 points in the latest major poll, and needs a miracle to win.

So, how did it all go wrong?

It started with a May 16 report that she had been accused of “stalking” her ex-boyfriend last year and trying to enter his house without permission. She survived the primary four days later, but her general election campaign got off on the wrong foot amid new reports that her ex-husband accused her of “ongoing harassment” in filings to police. Then came revelations that her health care plan was plagiarized from Karl Rove’s group. Pouring fuel on the fire, her new health care plan was also found to be plagiarized — from her former GOP opponent, whom she dispensed with by attacking him on health care.

Perhaps most damaging was her tendency to go underground when facing fire.

“The key moments were not necessarily the actual whiffs of scandal around Monica Wehby. They were her reaction to those whiffs of scandal,” Moore said. “They took three to five days to come through. So something would happen and there would be a deafening silence. Or in one case there would be a flippant remark like, ‘Dr. Wehby is busy in surgery saving children.’ So even if the voters weren’t following the actual whiffs of scandal, they certainly had a feeling that the campaign kind of disappeared when put under pressure.”

“You can look at a résumé all you want — she’s not doing the basic stuff you have to do to win a statewide race. Her campaign management looks to be borderline incompetent,” he said.

Vice President Joe Biden, right, listens as Sen. Jeff Merkley speaks during a campaign rally in Portland, Ore., Oct. 8, 2014. (AP Photo/Don Ryan)

Despite that, Merkley admits he was worried in August and September when the Koch brothers swarmed Oregon’s airwaves with millions of dollars in television ads bashing him as a debt-hiking tax-and-spender. While the ads were running over the summer, his lead shrunk in his internal polls. But by the end of September, even the Kochs gave up on Wehby, and her campaign has since gone downhill.

“It was kind of a brutal two months,” Merkley told TPM in an interview.

“Show me a candidate who’s not worried when the airwaves are flooded with an out-of-state powerful organization like the Koch brothers doing negative attack ads, and I’ll show you a candidate who’s not paying attention,” he said.

Wehby declined to be interviewed for this article, but her campaign provided a written statement to TPM, expressing cautious optimism about her prospects.

“Dr. Wehby is focused on turning around an economy here in Oregon where unemployment is above the national average, the labor force is the weakest it’s been in recorded history, and one in five Oregonians are now on food stamps,” said Dean Petrone, her campaign spokesman. “If voters take a hard look at where Senator Merkley’s policies have left them, versus where Dr. Wehby’s will take them, then our campaign has every reason to believe Oregonians will change their Senator on November 4.”

While Wehby has attacked Merkley throughout the campaign as a liberal ideologue, he has responded by bashing her as a generic national Republican who copies her ideas from Karl Rove and the congressional GOP. “She’s laid out a very clear right-wing agenda that included things like supporting a tea party budget that would eviscerate core programs in America,” he said. “She came out against [the] equal pay for equal work bill.”

“You had basically an Oregon values campaign that I was running and a Koch brothers values campaign that she was running,” the senator told TPM.

After the two candidates squared off in their only scheduled debate on Oct. 14, Merkley approached his opponent off camera and told her, “I think you and I will be the two happiest folks in Oregon when this campaign is over.”

Wehby agreed.