Eight months ago, I started an Eons group called Politics With Politesse to provide a venue in which people could discuss politics without the usual mud-wrestling. To succeed, a group like this needs some hard and fast rules: Absolutely no insults. No sweeping generalizations about "you Republicans" or "those liberals."

Some people never got the hang of it. Now and again, people would test the rules. I would warn them, and if they didn't agree to change their ways, I blocked them. Among the small handful of blocked people, about half were people whose politics were close to my own. Some of them came back under new names and tried to raise hell again.

It took some work, and no small amount of time, to keep things on an even keel. Sometimes I had to block people I really liked despite their wingnut qualities. Sometimes it was hard to judge whether someone had crossed a line.

For the most part, people seemed to enjoy having conversations on a wide range of topics -- health care, gun control, taxes, foreign policy, Cuba, you name it -- without attacks or name-calling. We shared our points of view and learned from each other. Every now and then, we'd find areas of agreement among people at opposite ends of the political spectrum. The members were passionate, but they were polite.

It was pretty cool.

But as the Democratic primary voting evened out between Clinton and Obama, things changed. One side became increasingly pugnacious -- not toward Conservatives or Republicans, but toward their fellow Democrats who supported the other candidate. It shaped up as a fight to the finish. I was told that I lacked understanding, that I didn't know history, that I should get real, that I should get with the program, that I was stooping to the level of the press, that this was about ridding Washington of "downright evil."

Good grief. I thought we were electing a president.

I thought for a day about how to deal with this. I could ignore it, but if the poisonous rhetoric went unchallenged, it would spread. Certainly I was under no obligation to maintain a venue in which people felt free to insult me. I could show the fanatics the door, but that didn't sit well with me. So in the end, I decided that the group that it had been was no more ... so I shut it down.