Kitzhaber, a physician, has been dogged by the failure of Oregon's state health exchange. Still, he was leading his Republican challenger, state Rep. Dennis Richardson, in the polls until early October.
Then came revelations about Kitzhaber's fiancee, Cylvia Hayes. Portland's Willamette Week published a lengthy piece questioning the private consulting work she performed as first lady. While reporting on that story, the paper discovered that Hayes had been paid $5,000 to take part in an illegal "green card" marriage in 1997 to allow an Ethiopian student to stay in the country.
In a tearful news conference in October, Hayes said her action "was wrong then and it is wrong now, and I am here today to accept the consequences, some of which will be life-changing."
Hayes and Kitzhaber have been together for about a decade and became engaged over the summer. Until the revelations broke, he was unaware of the marriage.
Hayes said when she told Kitzhaber about it, "he was stunned and he was hurt," but he was standing by her.
"And I will be eternally grateful for the beautiful, loving way he has supported me in this," she told reporters.