To be fair, political discussion worked much better here than other places I've seen on the internet, meaning that there was some actual discussion going on rather than just people CAPS screaming at each other.
Still, I'm glad you're ending it. For me, it was a real turn-off from the site. I've been participating here since before 3E's release and one of the big reasons I'm still here is that there are people here I chat with that I rather like. Well, with the politics experiment, I've seen that some of them are actually fairly dreadful people with really dreadful views on the world. With the political threads frequently on the top of the "all threads" view I've found myself less and less interested in coming here even to check out the RPG conversations.
That's true, and unfortunate.
I reckon it might even color how we view other topics we're discussing. So if PersonX hates TopicY that I like, is that why he's disagreeing with me on TopicZ. As well as now I really don't care for PersonX at all.
Interestingly, I've noted an opposite effect. There is at least one person in the political discussions with whom I strongly disagreed... who has repeatedly been giving me XP in gaming discussions while we were disagreeing on politics. I found that a bit refreshing.
Ah well, back to the discussions about how 5e sucks because there's no warlord and the ranger is horrible, how 4e sucks because it's too WoW like, how 3e sucks because it's for no one but min/maxers, and how AD&D sucks because THAC0.
I think that's great. I'd rather see people be able to discuss other topics and not carry grudges.