Mahmoud Ahmadinejad

What is the problem with letting Mahmoud Ahmadinejad speak at Columbia University or place a wreath at Ground Zero in New York?
What have we to fear? Is there anything he can say that we would not hear if he released a statement from Tehran? Are we so insecure in our country that we cannot hear opposing or even disreputable speakers?
Those who protest this visit do not seem to understand what free speech means. Allowing freedom of expression does not mean in any way a validation or a repudiation of the speakers views, it only gives a person the right to express those views. It will not hurt him that we denied him here, indeed it will probably elevate his status in the eyes of those who oppose us.
It will expose us as hypocrites to the world when we deny freedom of speech on our own shores.