Earlier quoted context omitted.
I'll never understand this - the ability to petition for the judge to disallow a valid defense, because they're scared it might work. That's the entire point of a defense. To me, this goes against every freedom of speech. To not be allowed to defend yourself in any and every way possible is to not be free. Edit: "in any and every truthful way possible" - obviously perjury is perjury.
He shouldn't be allowed to express political views during the trial. It isn't a valid defense because his political views are completely unrelated to the matters at hand. The only purpose of the trial is to determine whether or not he did the things the government says he did. If he did them, then he broke existing laws.
If that were true, there would be no such thing as Jury Nullification. As long as the concept both exists and is valid, a defense that argues the law itself is in fact a completely valid defense.