The social democratic kind has a long tradition of being in government and indeed working to further the rights and interests of workers and the low/middle classes. The communist kind has only ever been in power (on its own) in what turned out to be pretty nasty dictatorships with consistently horrible track records with respect to the commons. In countries with strogn social democratic traditions (most of Europe), they have become a effective 'reality check' (for better of for worse, YMMV) for the government left if it tended to go too rightist.
What I am saying is that the environmental movement has the same kind of split, and the the existence of the "hard left" kind is used by the right to deconsider environmentalism, just like the existence of the hard left is used to deconsider the left overall, even if its influence in the West is mostly benign and useful (as opposed to its role solo in government, where it has historically been not so benign). In the long run, we're all dead. John Maynard Keynes
What about that Indian state? Or Nepal before the royal coup? And re my original point, can all those pretty nasty dictatorships be treated as independent from each other (e.g. hasn't the devolution of the Soviet Union into Stalinism not had an effect on the movements that came to power later elsewhere) and from circumstances (like: war and intervention that begat a war mentality, as Migeru emphasized a couple of times)?
At any rate, the distinction you made is not between the left and non-left, but inside the left.
What I am saying is that the environmental movement has the same kind of split
If you check my comment on the German Greens' origin, you'll see that the picture is more complex. It was the power-conscious ex-violent-radicals who brought it towards the center, while those more radical on environmental issues were more peaceful (in fact many of them peace movement activists) and were pushed to the backbenches. The scale from SUV arsonist to fuel tax specialist (which may appear to you) is not sufficient to describe the different shades and radicalism of Greens, they are a bit different bunch from traditional hard leftists.
the existence of the "hard left" kind is used by the right to deconsider environmentalism
The right uses anything to deconsider leftist ideas, including lies, including about leftists and including about hard leftists, and sometimes it appears centrists and centre-leftists are buying into right-wing rhetoric when protesting their difference. This should be clear to you as per your own experience in debates at dKos (where for some by now you must count as looney-left both on the energy tax and relationship with Muslims). This is not to say that there are no radical environmentalists who say silly things (of course there are), but about taking the Right's judgements not unseriously enough. *Lunatic*, n. One whose delusions are out of fashion.
