First of all, “liberal” is a misnomer. These are people whose political views are left-of-center. They are not liberal in any respect.
Secondly, they have no interest in public discourse. They want to tell you what to do. See our present Congress as an example. The “liberals” have no interest in differing opinions. They prefer to persecute people who disagree with them. Trust me, I’ve been watching these people for forty years.
More recently, many of their ilk have reverted to a nearly 100-year old appellation, namely: "progressive". I find the term a preferable description for the Obamanauts, even though it wrongly assumes that Progress points ever Leftward. It does, however capture the overtly anti-business and Prohibitionist sentiments of an earlier age, where a loose coalition of socialists, communists and anarchists promoted Utopian visions of a New Man in a New World, much as do their descendants.
Inspired themselves by a philosophical tradition stretching from Rousseau to the French Revolution and the European uprisings of 1849, the first American generation of Progressives helped to unleash the historical forces that resulted in World War I, the Russian revolution, and, ultimately, the rise of Nazi Germany from the ashes of a once-stable, but suddenly shattered world order.