They are NOT stages of development. This image from Drexel University does a good job of explaining the differences between the two.
Just like introversion vs. extroversion, or thinking vs. feeling, liberal vs. conservative is an axis spectrum in typology, not in development. Obviously, I am talking more about philosophical perspective than political party, since Democrats and Republicans have very little correlation to being a liberal or a conservative.
Too many people (it seems to me) think of liberal as more developed and conservative as less developed (and I am guilty of this, too, on occasion). That's a false perspective.
I fully believe you can hold a conservative tribal worldview or a liberal tribal worldview, same deal with mythic, rational, and postmodern.
I'm sure many will disagree with this, but it's my theory (until proven false) and I'm sticking to it.