I got to thinking about what you said and I think I understand your point. Out of curiosity, I'm going to start keeping track of the opinion pieces in the RG and see how many "liberal" and "conservative" columns they run. I have to tell you, I am fed-up with the simplistic, partisan labeling that politics has become - left or right. People ought to be able to focus on the merits of specific issues/policies without classifying them as Republican or Democrat,  liberal or conservative, etc. But I realize that's not the world we live in.
I think Motley had a good post when he mentioned that the RG (and all newspapers) are a business and they are going to run stories, opinion pieces, etc. in their newspaper that people are going to buy. Otherwise, they go out of business. Since Eugene definitely has a "liberal" bent (there's the labeling again) it may not be surprising that they publish the columnist that they think most of the people want to read.