Since politics is heating up with the Health Care debate - I found a great speech discussing how and why Liberals and Conservatives differ (BTW he uses these labels for anyone left or right of center where as I would usually use these lables for people FAR off of center - but you'll get the idea)
Who doesn't love TED.com? If you haven't found it yet you are missing out!
Psychologist Jonathan Haidt studies the five moral values that form the basis of our political choices, whether we're left, right or center. In this eye-opening talk, he pinpoints the moral values that liberals and conservatives tend to honor most.