It is an interesting phenomenon that the response of the left half of our political spectrum to criticism and argument is often to try to shut it down. Thus President Obama in his Sept. 9 speech to a joint session of Congress told us to stop "bickering," as if principled objections to major changes in public policy were just childish obstinacy, and chastised his critics for telling "lies," employing "scare tactics" and playing "games." Unlike his predecessor, he sought to use the prestige of his office to shut criticism down.

Now, no one likes criticism very much, and most politicians would prefer to have their colleagues and constituents meekly and gratefully agree with them on pretty much everything. And yes, Rep. Joe Wilson did seem to have broken the rules and standards of decorum of the House (though not of the British House of Commons) when he shouted, "You lie!" in the middle of Obama's speech.

But none of this justifies the charges, passed off as cool-headed analysis, that Obama's critics are motivated by racism. There are plenty of non-racist reasons to oppose (or to support) the Democrats' health care proposals.

I would submit that the president's call for an end to "bickering" and the charges of racism by some of his supporters are the natural reflex of people who are not used to hearing people disagree with them and who are determined to shut them up.

This comes naturally to liberals educated in our great colleges and universities, so many of which have speech codes whose primary aim is to prevent the expression of certain conservative ideas and which are commonly deployed for that purpose. (For examples, see the Website of the Foundation for Individual Rights in Education, which defends students of all political stripes.) Once the haven of free inquiry and expression, academia has become a swamp of stifling political correctness.

Similarly, the "mainstream media" -- the old-line broadcast networks, The New York Times, etc. -- present a politically correct picture of the world. The result is that liberals can live in a cocoon, an America in which seldom is heard a discouraging word. Conservatives, in contrast, find themselves constantly pummeled with liberal criticism, on campus, in news media, and in Hollywood TV and movies. They don't like it, but they've gotten used to it. Liberals aren't used to it and increasingly try to stamp it out. Continued...