This is a very dense, academic book with a great deal of methodical presentation of evidence for his thesis. His later book, "Don't think of an elephant" is a distillation of the ideas put forth in Moral Politics with a more direct line drawn to the U.S. political scene in 2003 and 2004.
I found it helpful to read these two books because the shorter "Elephant" is supported by the (excruciatingly) academic "Moral Politics" and "Moral Politics" is tied together nicely by "Elephant".
I know that Lakoff has been trotted out by liberals in the political theater here, but it I would hope that all areas of the political spectrum could have an honest discussion informed by the psychology understood in this book. It really does lay out a useful pattern for discussing sincere policy differences without resorting to the intellectual dishonesty of most of what passes for political discussion these days.