League of Conservation Voters
The League of Conservation Voters (LCV) is the political voice of the national environmental movement and the only organization devoted full-time to shaping a pro-environment Congress and White House.
The LCV is a C-4 organization - a nonprofit corporation, but not tax exempt, because its work is intended to influence legislation. The national LCV is matched by the League of Conservation Voters Education Fund (LCVEF), a C-3 corporation, which performs voter education work that is entitled to be tax exempt.
The LCV has published a National Environmental Scorecard every Congress since 1970. The Scorecard is the definitive record of how members of Congress voted on the most important environmental legislation before them.