Your description of where the US Green party is working in the moment, is exactly how te German Green party started out in Germany as well. local activism, election into district, regional parliaments. but then there was the PR, but i understand, there are states, that vote (internally) also with PR, or at least on some district level?
Except their leadership was taken over by that motley collection of unreconstituted left wing radicals (Marxists and anarchists), who then quickly reconstituted themselves, for example becoming ministers :-) (See Fischer above. It is noteworthy that much of the original 'Realo' wing started out as far-left rather than environmentalist, and just the opposite for the Fundis.) *Lunatic*, n. One whose delusions are out of fashion.