Regarding you other point about whether or not it’s “right” for Columbia to allow such speech: You may not like the fact that Columbia gave Ahmadinejad a platform to speak, but our 1st Amendment was written exactly to protect speech that might not be liked by the government. Whether or not you consider it “right” or not is immaterial. To use your example, if you want to parade around proclaiming yourself the second coming of Jesus, have at it! However you cannot force me to listen to, or accept you are in fact Jesus. The same holds true of Ahmadinejad appearance at Columbia. No one held a gun to your head and forced you to listen.

When we have the government (Federal, State or local) dictating what is or is not an acceptable topic for public discourse, we will be exactly like Iran or Singapore, China, or any other state that is so insecure that it cannot tolerate differences of opinion or ideas that run contrary to its official state dogma.

By giving Ahmadinejad his 15 minutes in the spotlight, Columbia (with the exception if the poor performance of Columbia’s President) allowed the public to see how out of touch the Iranian President is… More speech is always a good thing: from crazy people it allows us to see and understand how crazy they are, and from good people it allows us to get the benefit of their insights. At the end of the day, you have to ask yourself why are you so afraid of letting Ahmadinejad speak? In the end, did he help his own case or hurt it?

I would suggest that you do a little reading and exploring of history - first about the history of American government. The Federalist Papers is a great place to start — It’s a series of essays in which Hamilton, Madison and Jay debate the merits of the US Constitution to a skeptical public before its adoption in 1789. From there look at the history of Russia and the Soviet Union, China, and other countries where the state dictates thought and speech.