The legal philosopher Michael Sevel (Sydney) calls this to my attention, and gave me permission to share the letter he sent to Amazon (others should do the same): 

 "Dear Amazon,

I write in regards to a volume entitled Barbarians: How the Baby Boomers, Immigration, and Islam Screwed My Generation, by Lauren Southern, available on your site in both Kindle Edition and Paperback:

https://www.amazon.com/dp/B01MU30NB0/

I spotted this title, both editions in fact, at the top of your list of Best Sellers in Political Philosophy:

https://www.amazon.com/…/bo…/11065/ref=pd_zg_hrsr_b_2_4_last

This 61-page document is not a work in political philosophy, in any sense of the term. Political philosophy is a sub-discipline of philosophy. This is not a work of philosophy, in any sense of the term. While characterizing the distinctive features of philosophy in the Western tradition has itself long been a lively topic among philosophers, it is in every guise marked by a mode of argument the point of which is the discovery of general and abstract truths. That mode of argument is manifested in standard forms of reasoning, for example, in establishing, with evidence, a number of premises the acceptance of which logically requires the acceptance of the truth of a conclusion those premises support.

No argument of that sort can be found in Ms. Southern’s volume. Nor is there any evidence of a concern for truth. This volume, or any part of it, would be completely unacceptable if submitted in any introductory philosophy course anywhere in the world. It is, rather, a hyperbolic, and vitriolic, expression of certain political attitudes which have become fashionable during the recent U.S. Presidential Election. Indeed, this volume’s rise in the rankings of “Best Sellers in Political Philosophy” has not gone unnoticed by others who share such attitudes. See for example this recent Tweet by a person who has identified with the so-called “Alt-Right,” boasting that this title outsells Plato:

https://twitter.com/Cernovich/status/812066375795544064

This Tweet has been retweeted over 150 times, by people who ironically appear to be concerned about the promulgation of fake news.

Ms. Southern’s essay is fake philosophy.

I strongly urge you to revoke your classification of this title as a work in political philosophy. Classifying it as such is simply false, both as a description of its contents, and as a representation of what political philosophy is.

I also strongly urge you to review your practices regarding the subject matter classification of books going forward, to avoid further misleading Amazon customers.

Yours Sincerely,

Michael Sevel
J.D., Ph.D. in Moral, Legal, and Political Philosophy
Lecturer in Jurisprudence
Sydney Law School
University of Sydney
Australia"