Also, many religiously-oriented volunteers were burned by the lack of results of their political activism in the last cycle. Eschewing the corruption of politics in general, many have returned to saving souls instead of recruiting for politicians. Pat Buchanan did his part by riding off into the political wilderness to seek supporters in non-battleground states. The Democrats didn't even seem to realize they had a problem with Nader dividing workers and environmentalists. A lot of people like to think of themselves as environmentalists, but that doesn't mean they vote that way.
Reasonable people can disagree on solutions to complex environmental problems.
Unfortunately, too many still think it doesn't matter, or it doesn't matter to them. The vast majority of environmental groups are nonprofit educational groups and cannot do politics the same way that business groups do. Environmentalist cultures are rife with factions and divisions. Diversity is valued over unity, and this is healthy, to some degree. But this could be their political undoing in a system requiring unity to achieve power.