[dragonwriter]

> OK, I don't know anything about US laws, but I really don't understand it. How can a judge forbid mentioning constitution or amendments in court?

It seems to me that what happened is that the argument (which is one of law, not of fact) has already been made in court prior to the trial. The judge has rejected it, and prohibited it from being raised in the trial (and thus, to the jury) as it is immaterial to the questions of fact the jury is to decide.

Of course, if there is a conviction, the judge's rejection of the argument can be challenged as legal error on appeal.