Centrist? Non-partisan? Moderate?
What does this have to do with politics? There is no such thing as a political moderate.
Most social and political issues are binary; that is, you can either support it or not. Take abortion for example. Many who favor allowing abortion like to call them selves pro-choice advocates. There is no point in trying to fool others. They certainly aren't against abortion, so all that leaves is being in favor of it. There may be different degrees in amount of support, but unless someone just does not have an opinion on the matter, they cannot claim to be anything but partisan.
Then, let's say we take an issue like President Bush's original Social Security fix. Again, someone can be in favor of it or not. Taking these two issues, there are four possible viewpoints. So, being in favor of the Social Security fixes and abortion, or the opposite might be seen by some as "moderate". But is it really, or is it just having viewpoints which are still partisan, though on different sides? Just as in the vector of 3i-3j, differing political viewpoints do not add up to zero. Add in hundreds, perhaps even thousands, of other issues, and acheiving moderation simply is not possible.
"Moderates" take issue with people on either side for different issues, but rarely, if ever, do they take issue with the viewpoints of both sides. A moderate, by definition, would be different from those on both sides. If you are looking for someone with a true moderate viewpoint, find someone who has no opinions.