Is it's ability to redefine eternal truths on a dime. It takes a long look at society, and notices that society affirms Value A. It then begins declaring that Value A is the most heinous, most horrible, most unthinkable gawd awful value in history, the sum of all evil, the singular cause of all suffering on the planet. It then beats a drum over and over and over and over again about how horrible Value A happens to be. It makes it clear that only the worst people, the meanest, the most hateful and ignorant people would ever, ever embrace Value A. It does this until Value A is all but extinguished, and any who even come close to associating with Value A are ostracized.
And then, once it's in the drivers seat, it turns around and not only embraces Value A for itself, it then goes onto use the lamest defenses for doing so, hoping that the society it birthed is as stupid as one might imagine a society built on such things would be. Best defenses for Maher's statements: Whoopi saying 'retarded was once OK to use, so what's the problem? It took most carbon based lifeforms about 2 seconds to see the irony in that standard. And Barbara Walters leaning on Maher's incomparable stupidity: he couldn't possibly have known the word is offensive.
Which is also another favorite tool more common among the progressive than the traditionalist: plausibly stupid deniability. Say something soaked in sexual euphemisms, and then declare ignorance of it while giggling behind everyone's back. Say 'Maher couldn't have known the word is offensive' when, for decades going back to the glory days of 70s liberalism, the word was repeatedly declared by liberals to be offensive.
It isn't easy fighting against an ideology that rejects foundational values as a matter of course. An ideology that change its morals more often than you could change the diapers of a baby on a three week long beans and broccoli diet. This little story demonstrates why.