In 1946, George Orwell published his famous essay “Politics and the English Langugae”, decrying what he saw as sloppy writing driven by lazy thinking. His argument was the English Language “becomes ugly and inaccurate because our thoughts are foolish, but the slovenliness of our language makes it easier for us to have foolish thoughts.” Orwell makes it clear that he has "not been considering the literary use of language, but merely language as an instrument for expressing and not for concealing thought.” Despite his injunction, we can see that in the intervening seventy years, very few have heeded his advice. Chief among language's abusers have been academics and politicians.
The Tyranny of Cliches, is a sort of spiritual successor to Orwell. After numerous speaking engagements (and, most likely, watching a lot of cable news), he started to notice a trend. People mouth all sorts of cliches (“I disagree with you, but will defend your right to say it”, “Violence never solved anything”), defending principles they haven't really thought through. These outbursts are a way to avoid arguments by not even making them. People invoke these cliches as placeholders for arguments not won or ideas not fully formed. And these are usually the same folks who denounce a truly thought-out position as “ideological”.
Anyone familiar with Goldberg's columns knows he makes his arguments with a combination of serious research and humorous pop culture references. He's a writer who is at home quoting anyone from William F. Buckley, Jr. and Thomas Sowell to Jean-Luc Picard and Ron Burgundy. In the span of two paragraphs in his chapter on ideology, Goldberg references Fredrick Hayek, Ludwig von Mises, and Steven Bochco's Cop Rock. We're all familiar with parents hiding medicine in applesauce to make it more palatable, well, Goldberg's writing is like hiding your medicine in a hot fudge sundae.
Each chapter takes on a hoary cliché and shows why we shouldn't just accept its argument at face value. Quite often, his research shows that the original formulation of the cliché has very little direct correlation with the currently accepted meaning. For example, the phrase “social justice” is used quite often these days; from politicians to charities to civic organizations and labor unions, hell, even the American Nazi Party uses the phrase in their mission statement. A cry for social justice is usually little more than a cry for “goodness”, however goodness is defined by its wielder.
The phrase social justice began as a technical term within Catholic theology, coined around 1840 by theologian Luigi Taparelli d'Azeglio as a way to emphasize that much of the important stuff in life lay outside the realm of the State.. Human beings are social animals, belonging to more institutions (read: societies) than just the State. These societies maintain a level of autonomy apart from that of the State. The State has a responsibility to not “destroy the inner unity” of these societies, but rather they must respect their freedom and autonomy within the society. In other words, the government cannot trample the structure of social ecosystems that make life worthwhile. It had nothing to do with redistributing wealth (never mind fighting for gender equality). Taparelli thought of and employed social justice in a completely different way than almost everyone does in contemporary society. 
This is just a brief example of Goldberg's core thesis. The first couple chapters are a fabulous piece of work showing that the high-minded-sounding phrases of pragmatism and “no labels” and the disdain for ideology and dogma are nothing more than nonsense on stilts. After this point, each chapter is a mini-essay, some are better than others. I loved the chapter on dogma, but his attack on the phrase “power corrupts”, was lacking. He started off by showing where the phrase came from, then devolved into attacking the late Senator Ted Kennedy.
One great thing about this book is that it's wonderfully browseable. You can pick up and read any chapter at any time without missing a thread of an argument. This also leads into one of my nitpicks: the book is not homogeneous. I would've liked if he tried a little more to bring the book under more than just the broad umbrella of attacking cliches, or at the very least write a concluding chapter to tie it all together. The introduction is wonderful and carefully lays out his thesis, so it would've been nice to have a complementary chapter at the end.
Since Goldberg is a conservative author, the majority of cliches he debunks are used by those on the left. He does tackle some cliches the right uses, like "slippery slope" arguments, but not too many.
There are a number of chapters that I'd like to reread and internalize their arguments to use against the gauzy nonsense spouted by many. Other chapters, I'll leave alone. If you're a fan of Goldberg, you should get the book. If not, I'll show you which are the best chapters.
Side note: Shortly after the book's release, Goldberg did an interview with ReasonTV. He talks about the book, the founding of National Review Online, and some other topics. It's really a good interview that you can watch here. Here he is in his own words explaining what the book is about:
"Liberals are sure they're in the reality-based community and anyone who disagrees with them either has a bad brain, or in some other way rejects empiricism and science, and they are the only ones working with the building blocks of facts and reason. And I call bullshit on that."