There is not a law, per se, against jury nullification, but as I think you well know, juries are instructed by the judge not to consider legal issues and to base their verdict solely on the facts. If the judge finds out that the jury did not do that, and rendered a not guilty verdict that should otherwise have been guilty merely because they disagreed with the law involved, the jury members could be jailed for disobeying the judge's instructions.
I would like to see some corroboration of your statement that no juror has ever been prosecuted for engaging in jury nullification and admitting that he did so.
No it is NOT "perfectly legal" if a jury chooses to ignore a judge's instruction. We seem to be dancing around this term, "legal" in the context of this discussion. You apparently think that because there is no express, criminal statute which prohibits jury nullification, it is, therefore, "legal" for juries to do it. OK - if you want to make that the test, then yes, it is "legal" in that sense. But you are conveniently overlooking (1) instructions given to the jury by the judge and (2) the sanctions available to the judge if those instructions are not followed.
The inside of a jail cell doesn't really care whether you got there for violating an express statute or a judge's instruction - it's still the inside of a jail cell.
Where on earth did you get the idea that if a judge becomes aware that his instructions were ignored by the jury and a nullification verdict was rendered, there is "not a damn thing he can do about it." There sure is. He can declare a mistrial and throw the entire jury into jail for contempt of court.
The operative phrase there is "becomes aware." Sure, if a jury renders a nullification verdict and no one breaks under questioining from the judge and cops out to the real reason for the verdict, then I suppose there wouldn't be anything he could do. But, as I mentioned in a previous post, it is highly unlikely that anything like that would ever happen.
You have any verification of your statement that no juror has ever been sactioned for engaging in jury nullification and admitting he did so? I didn't see that anywhere in your response here . . .
You seem to think that your duty, as an officer of the court, to uphold the law, even if you think it is wrong,somehow binds the jury that reaches the same conclusion. I would love to see you explain that one.
I don't think the instructions which prohibit juries from considering the law are wrong. I agree with them. We don't need juries undoing laws by rendering nullification verdicts. If you don't like the law, get it repealed. As long as it's on the books, right or wrong, it's the law. Encouraging jury nullification verdicts is a step torward anarchy.
What would I do if I felt a jury had rendered a not guilty, nullification verdict in favor of my client? Nothing. When it comes to a conflict between my duty to my client and my duty as an officer of the court, the former almost always wins out.