I came across this article on DailyKos yesterday:

http://www.dailykos.com/story/2009/2/24/04124/0642

Ultimately, it's an analysis of Obama's speech from last night by a linguistics professor, but in the course of that analysis he gives perhaps one of the most clear and accurate descriptions of the fundamentals of what progressives believe, and how the specific policy positions progressives have stem from those underlying principles that I've read.

In a related note, here's the word cloud for Obama's speech:

And the cloud for Jindal's response:

You can see the difference between the parties pretty clearly, just from that alone.