Who is to say he can't ? Kulongoski is an almost certain bet that he won't get as many votes as he did the last time. If Mannix gets virtually the same as what he got last time, he wins.
Lets see he hasnt in 3 state races, theirs even less republicans and hes the most polorizing republican probably in the state. Plus theirs not 35% republicans in Portland so you need someone who can get the indepedents and a few democrats and I believe Atkinson can. Go check out Blue Oregon (lefty site), many people on their are gonna vote for Atkinson, and they say like I said democrats dream guy is Mannix, he will fire up the democrat base.