Lakoff draws his examples largely from the context of the US political system and he makes no effort to conceal his Democratic leanings. Certainly not unbiased, the book is in fact a call to arms for Democrats, who Lakoff claims are decades behind Republicans in their understanding of these issues. All this means I take his words with a grain of salt.
Nonetheless, the discussion of mental framing and its effects fits with my observations of the world and seems broadly relevant. His analysis of the progressive and conservative movements themselves and their origins was also intriguing: I have no idea how accurate these theories are but I was able to look at conservative policy in a new light.
I was annoyed throughout by his repetition, both within and between chapters. In a few cases, I discovered several-paragraph-long sections that were taken almost verbatim from an earlier chapter. I discovered part way through that the book is a collection of essays and I have the impression they were thrown together quickly to get the book published in time for the last US election. This is partly to blame for the repetition but I think Lakoff is also overapplying one of his own messages: that mental frames are adopted through repetition.
That said, the book is short (100-and-some pages), cheap ($8 on Amazon), interesting, and a quick read so I recommend picking up a copy even if you only make it through the first two chapters.