Far too often I hear the Sierra Club condemned for not endorsing Greens. While it is not as common as we would like, since we believe that the Green Party has more in common with the goals of the Sierra Club than any other party, it does happen and even in partisan races. The most recent Sierra Club endorsement has gone to Marnie Glickman. While the Las Gallinas Valley Sanitation District is a not a partisan office, we know what it takes to gain these endorsements.
I even remember Tom Hutchings, a San Luis Obispo County Green, getting Sierra Club endorsement for State Assembly Dist 33 in 2004 after years of supporting efforts to block the expansion, if not able to close, the Diablo Canyon Nuclear Power Plant. It can be done, you just have to work at it.