Thought 4: Generally, those sorts of people tend to not be serious rationalists. Reasoning as if I can expect correlations among our decision algorithms seems questionable.

No kidding.

If I were you, I would first concentrate on getting the other jurors to reason correctly about the facts of the case, which is, ahem, enough of a problem.

(Though apparently -- and outrageously -- one has to be careful here: I know a mathematician who once served on a jury and was accused of juror misconduct for presenting "facts not in evidence" to his fellow jurors, namely "the mathematical theory of probability"!)

With regard to the moral issue of nullification, it seems to me to be quite clearly a quantitative issue of how egregious the law is and how draconian the punishment is likely to be. By no means do I see any general policy of the form "always nullify when you don't like the law" or "never nullify" as reasonable.

I'll explain the case against an "always nullify" rule, since I expect that will be more counterintuitive to most folks here.

Getting a society's rules to be codified into written law represents great progress, in the overall scheme of things. Back in the old days, whether you got to live in peace or thrown into a dungeon and your head cut off was determined by whether the overlords liked you or not -- and the rules for pleasing them weren't written down anywhere, certainly not in any form such that you could appeal to them and say "but you didn't follow the rules!"

Well, that's still fundamentally the case, except that we've gotten slightly better about it now. There are written laws, and, at least in theory, there are courts where you can go and say "but the government's position is incoherent!" and have that actually, you know, matter. But much of this formidable-looking edifice of a legal system is still something of a fiction. Laws are still written without the intention of their being taken literally, or even necessarily enforced at all: they're there so that the authorities have a "legitimate" pretext in case they decide they don't like someone and want to go after them. And there are so many laws, of such obscurity, that essentially everyone is probably violating a bunch of them, and so at the end of the day we're at the mercy of the people in power just like we always were. It's not quite as bad as it was in the old days, but the difference is merely quantitative. We still have further progress to make toward the ideal of explicit rules that will protect us from the arbitrary caprices of The Man.

Now what does this have to do with jury nullification? Well, consider which direction on this axis you're pushing in by adopting a policy of disregarding the written law and making policy ad-hoc while in a role not legally authorized to be a policy-making role. You may think you're helping to correct an imperfect set of rules -- and perhaps you are -- but you're also at the same time helping to enshrine the notion that the text of the written law doesn't really matter. If people thought the law actually mattered, they'd be much more careful about which laws they passed. However, as long as the notion persists that laws need not be taken literally, legislatures will continue to pass symbolic laws that will be enforced unsystematically, making everyone -- particularly society's envelope-pushers -- continually vulnerable to the whims of prosecutors and the like.

People being convicted of violating unjust laws is a much, much larger problem than people being improperly acquitted. Both because one improper conviction is worse than one improper acquittal, and because I don't actually think improper acquittals really happen much. Opposing jury nullification seems to me like a status move to maintain the power of the lawyers, at the expense of justice.

So if you're on the jury for a case prosecuted under an unjust law, then yes, you do have a moral duty to acquit. Whether you should announce that it's a jury nullification, or lie about how strong the evidence looks to you so others don't get the same idea, is less clear. I lean towards the former.

Surely posting about it here makes it a matter of ordinary repeated games, TDT or not.

Thought 3 is where you make a mistake. You're not choosing for jury members who won't convict on hate crimes. You're only choosing for future jury members who have a similar choosing alorithm to yours. The haters obviously don't. Thus the only thing you need to ask yourself is: Do I want future jury members with similar ethics to mine to convict on drug laws or not? And that's your desicion.

Edit: But as Unnamed wrote, the difficult choice is what to say during jury selection.

Another question is what you should say during jury selection. What if they ask your opinion about drug laws, or if you will be able to faithfully & impartially apply those laws regardless of your opinion?

Humans don't run TDT. Do the right thing for the case you are presented with.