Nonsense. The danger the country faces is from the government (a non-person) deciding that its favored corporations (General Electric, New York Times etc) get speech rights while other organized groups (local flower clubs) are silenced by force of law. The book is is hardly "thorough" -- it fails cite the text of the First Amendment, the most relevant source of law to the controversy.
I noticed that Mr. Clement also deletes comments at his corporate-sponsored blog. He hates the free exchange of ideas. What a pathetic hypocrite.