Since the textbook does not provide a good discussion of Government Failure, the following free links will be used as the textbook for Government failure, often called Public Choice Economics.
http://en.wikipedia.org/wiki/Rational_ignorance This link talks about how it may be rationale for you to remain ignorant, which of course is sub-optimal for the perspective of the overall society.
http://en.wikipedia.org/wiki/Public_choice_theory Is an overview of Public Choice theory, which takes as its basis rational ignorance. The main claim, government is an underprovided public good. (Theory and Claims are the most important sections to look over for the purposes of this class).
http://en.wikipedia.org/wiki/Median_Voter_Theory. The median voter theory discusses how some politicians will "run to the middle" in order to maximize the possibility of being elected. But what if the optimal policy lies somewhere else besides the middle?
Update: This article does an excellent job of explaining public choice economics. http://www.econlib.org/library/Enc/PublicChoiceTheory.html