I've been moderating blog comments here with a very light touch. But the interactions have gotten so rough that it's obvious a heavier hand is needed. So starting immediately, there will be new guidelines. (And they are on permanently display under the "Commenting guidelines" heading under "Pages.")
I reserve the right to delete comments or block certain commenters based on a failure to follow these guidelines:
1. Stay on topic.
2. Avoid personal attacks and ad hominem arguments.
3. Keep the foul language to a minimum.
Those don't cover everything but should make the goal clear: Come here in the spirit of lively debate rather than nasty vituperation. I'll generally give those who already have comment approval a couple of passes on violations, blocking them on the third one. But if it's bad enough, I won't feel obligated to show patience. Those who have never commented here before and want to get ugly on the very first try — please don't waste your time or mine.