'Politics' is a massive category, and has a disproportionate share of the important issues (relative to, say, randomly selected academic topics). In the long run (assuming there will be a long run), reinforcing the intellectual norm that politics is low-status and impossible to productively discuss is surely a bad thing if we think that it's at all important to get political questions right. It will function to make politics increasingly intellectually impoverished and divisive, as we keep seeing more and more of the calmest and sanest thinkers avert their eyes from politics and from political theory.

Because politics is so dangerous to talk about, especially high-level rationalists should be encouraged to practice their craft on it sometimes, to improve the state of the discourse, contribute important new ideas to it, and further hone their own knowledge and anti-mindkill skills.

That said, I agree that at this moment the risks of a politics open thread on LW probably outweigh the benefits. I would suggest instead an off-site politics discussion forum maintained by passionately dispassionate LWers, intended for discussants and posts with LW-like quality levels and topics. (If there already is such a thing, do let me know!) Since it would be off-site, there would be less risk of bleed-over, particularly since we'd have flexibility to implement extreme measures like:

• there are no public usernames, and users are discouraged from giving identifying information in their posts. So posters will not be easily identified with specific LWers, and the forum itself won't tend to coalesce around clearly defined personalities, making tribes relatively amorphous and individual posts difficult to ad hominem.
• there are private user accounts, i.e., the forum won't be open to unregistered users. This makes it possible to implement a karma system, and to strongly restrict the posting privileges of new visitors until they've repeatedly proved their lack of mindkill.
• to make it possible (though not too easy) to prove that you're the same person as a previous poster, we can introduce a special tag that, e.g., makes you able to type #4F33301 in red iff you are the user who made post 4F33301. So in special circumstances identity can be maintained without risk of impersonation. You can also refer back to 4F33301 in black if you want to clarify which post you're responding to.
• but instead of serial numbers like 4F33301, let's use random dictionary words like 'vial' or 'fittingly' to mark individual posts, because that would be way cuter and easier to remember.
• in fact, optimize for cuteness, quirkiness, and friendliness in general, as much as is possible while maintaining anonymity. The friendlier and funnier the site looks and feels, the more light-hearted and collaborative the posts will be. professionalism and silly benign emoticons are totally compatible.
• to make the karma system more useful, we can introduce community guidelines to the effect that you should upvote for good methods, more so than for Correct Beliefs. (To encourage this we can use framing like 'Useful? Not Useful?' as opposed to 'Vote Up? Vote Down?' or 'Like? Dislike?'.)
• karma will determine how visible your post is, but the actual karma number of the post itself won't be visible to anyone. So you'll get a general sense that you're doing a good job if you see your posts rising to prominence (or, perhaps, a private aggregate per-user karma number increase), but there won't be as much of a temptation to fixate on points as there is on LW.
• the politics forum will rely largely on top-down moderation, probably even more so than on karma. Moreover, getting your post readily visible on the site will be a mark of privilege and of exceptional poster quality, not the norm. Mindkill posts will be deleted without mercy or hesitation, and borderline/mediocre posts will be more readily hidden on the site than they are on LW. (Possibly all posts will require moderator approval, or moderators will have an easy shortcut to hiding the posts, e.g., giving massive downvotes.)
• users will be strongly encouraged to routinely report all site abuses, and will be strongly and swiftly punished for feeding trolls even in cursory ways. (Part of becoming a user with full site privileges might even include a trial run of proving you will actively report problem posts without replying to them.)
• users who don't use the karma system in a way that overall improves the site will have their voting ability taken away and all their votes annulled. So the ability to downvote or upvote itself might become a privilege rather than a base-level expectation for users. If the user base is amazing enough, high-level poster privileges might smoothly transition into moderator-style privileges.

What do you think?