First, we need to define the term "liberal." The modern American "liberal" is nothing like the classical liberal of the 19th Century, who gave us most of modern civilization, nor even the anti-statist liberals of the 60s, who were well-intentioned if a bit naive.
The modern American "liberal" is a statist cocksucker who cannot tolerate even the existence of dissent. They claim to be "tolerant," but a quick discussion will lead to them admitting they don't have to tolerate those hatey haters who hate, which is anyone they disagree with, even if the facts conclusively support the other party. They are a cancer on society and, as in several past societies, at some point they will have to be exterminated.
Strong words? These are the people who will riot and shut down a campus to avoid even the presence of a gay man they disagree with. It wouldn't be a problem if they simply refused to attend, and thereby maintained their ignorance (a valued liberal trait). No, the very existence of a speaker who they've never actually heard, but have been told by their collective will say things they disagree with, is unacceptable.
This behavior is not "liberal." It's just like when the USSR claimed to be a "Democratic republic."
Check out the rest on his blog page. Then read his other entries. And while you're at it, buy some of his books, they're great!
(Yes that was a shameful plug...I just love his wit and writing ability)