I have spent two rather long posts giving definitions of various political beliefs like socialism and libertarianism. Any political belief system is a flowing river; the word liberal today does not mean what it meant 100 years ago. In fact, the word liberal has a different definition today for Americans than it does almost anywhere else in the world. Communist doesn't mean the same thing today that it meant in the early 19th century. Even the idea of democracy has changed over the centuries.
If you read the Wikipedia entries for the definitions I use, you'll find that there are many disagreements about what a particular philosophy really says. Also, people on all sides of an issue will use the same word to mean different things. Capitalism has one meaning for a libertarian, and a very different meaning for a communist. This often makes communicating difficult, and is why I decided to define the terms on my blog, so we can all be more or less on the same page.
Also, each individual has their own interpretation, and has personalized their political beliefs. As much as people like to hurl the accusation, there are in fact few robots - people who follow the party line in every particular with no deviation. There are differing degrees of thinking, of course, and many times people in all streams of political thought do merely repeat what they've heard from "their side." But in my experience, people tend to do this in areas they don't know much about, not in every area.
Anyway, the point of this post is that it is difficult enough to define a political philosophy. Defining individuals is often futile. Individuals define for themselves what their political philosophy means in their individual lives. They do not necessarily believe every key point in some encyclopedia discussion of their philosophy.
It bothers me in discussions when someone assumes that because their opponent is in some category, their opponent must believe X, and then attacks them for it. Best to ask first, and find out what that individual really believes. This saves time, and improves the accuracy of your arguments. It is also more civil, and we need more of that these days.