I understand why it happens, and I am a registered republican, but that's mostly because I align most with small government and low regulatory environments philosophically. In practice, my voting record is probably some random smattering of blue, red, and green. I vote for the candidate I think is best, and I try to evaluate all candidates based on their positions before looking at their party affiliation.

But also I live in the Portland, OR metro area so my vote is pretty much irrelevant.

Well, then you should be voting for the party which will change the voting system.