Few people know enough about neuroscience to agree or disagree with Lakoff's description of its discoveries, but nearly everyone can use what this book teaches as a recipe for dealing with people who, to us, seem irrational in their political choices.
I think it is very likely that Lakoff has his science right, or at least right enough. Can anyone reasonably say that the centuries-old concepts of how mind and language work are not as obsolete as their contemporaries, the theories of phlogiston and of the Great Flood? Whether Lakoff's brain science is exactly right matters little; it is sufficient to give a scientific foundation to think more effectively about how people think. Science continually evolves, and for today it suffices to take today's preliminary results to develop a useful technology of persuasion; waiting for a perfect knowledge that may never come is a recipe for failure.
More important than the precise rightness of Lakoff's formulation is its utility. Who has not found it frustrating to lay out fact after fact, logical argument after logical argument, and still to lose in the matter of persuasion? How many times I have drawn the conclusion that the listener was insincere, deluded or stupid! And never have those conclusions been especially helpful; no-one has ever been persuaded by being called "Stupid!"
Lakoff's explanations are much more useful than simply blaming the listener. It is very likely that people who brush aside my logic are almost never being stupid; they simply have a very different frame of reference and way of thinking. And since all thinking is based in biology, there is a biological basis for that thinking.
(Lakoff's description of the biology is interesting for those who like that sort of thing, and can be skipped by those who don't.)
As Lakoff notes, whether "they" are being "rational" or not is completely irrelevant! They think the way they do, and I can't magically expect them to change by mere logical argument. I can fail to respect their frame of reference, their way of thinking, the way they are built; and with that choice, I will fail. And (going beyond Lakoff) may I add that I would deserve to fail, for being disrespectful.
Or ... I can accept our differences, and work with them, gradually changing the way they think over time.
There is no magic formula for persuading people to agree with me (...and it would be frightening if there were. Think about it!) But Lakoff's recipe for action offers hope: offer alternative frames, non-authoritarian ways of thinking about the problems that matter, thus gradually getting people used to non-authoritarian conduct.
We often do this without knowing it. It's the heart of every potluck supper, neighborhood watch or other volunteer community organizing event. Really, "all" Lakoff does is give us a metaphor for thinking about what works, so we can implement the methodology effectively. But since thinking is fundamentally the use of apt metaphors, perhaps that's all Lakoff needs to do.
Putting the metaphor to use is up to us.
Hear Lakoff speak on the subject!