If you’re interested in the politics of drugs in the U.S.,
here’s an easy read:
http://thoughtcatalog.com/2012/lets-talk-about-legalizing-pot/
but the gold is all in this book:

The New Jim Crow, Michelle Alexander
This book is insane! It published in 2010 and has already influenced some legal changes in marijuana, and preachers are preaching from the text!
(http://www.nytimes.com/2012/03/07/books/michelle-alexanders-new-jim-crow-raises-drug-law-debates.html?pagewanted=all)
If you can’t get your hands on this book (which really, I promise, will mess with your head so bad), here’s an article that sums up her arguments (but still not as golden as the book itself, of course):
http://cannabisculture.com/v2/content/2010/03/10/New-Jim-Crow
Again, I urge you to read the book. Her argument is extremely well crafted, especially with the beginning chapters when she dives into the political history of the drug war and reveals a disturbing pattern that continues till today. She also takes you through the entire criminal justice system procedure that gets you questioning how far America has really come (in racial terms). Plus with the whole Trayvon Martin shebang, her argument cannot come at a better time.
The world can be pretty ugly at times; always question the social construct of …anything.