The Washington-based environmentally centric League of Conservation Voters on Tuesday morning has scheduled a conference call with reporters to announce a “six-figure” independent expenditure campaign against Republican U.S. Senate candidate Linda McMahon. Navin Nayak, the LCV’s senior vice president of campaigns, will tell reporters that McMahon is the newest member of the organization’s “Dirty Dozen” who “consistently vote against clean energy and conservation and are running in races in which LCV has a serious chance to affect the outcome,” according to the LCV’s website. Currently on the list is Mitt Romney and Sen. Josh Mandel of Ohio. “Since 1996, more than 60 percent of the Dirty Dozen have been defeated,” the webist says.