Spinnaker
Just had a look - couldn't find anything vile or bigoted
Perhaps politics is like beauty - in the eye of the beholder 
It's not much different to other SM platforms.
A couple of years ago or so I did lurk there awhile and there was one particular poster who had, shall I say, very "strong" views - on quite a few things and did dominate certain threads, so I decided not to join.
I don't think it's as good as GN though. We seem to have a much wider scope and variety of topics and - dare I say this - some much more knowledgeable posters, well-informed and articulate... from both sides of the political divide.
I think GN is on the whole far more civilised than many SM sites.