I thought about posting this to the 2016 Presidential thread, but seemed like too much a tangent. I think it is a great graphic for one-stop-shopping on political history of the USA and how issues have shifted over time, especially the demographic and political content of political parties over time. Heading into another election is a good time to get some perspective. I could spend hours dissecting the various pieces of this:
http://xkcd.com/1127/large/and a smaller version:
http://xkcd.com/1127/