"Former U.S. House Rep. Pete McCloskey, co-founder of Earth Day and co-author of the Endangered Species Act, is endorsing David Gill. In 1972 McCloskey ran as a Republican against Richard Nixon as the anti-war candidate. In 2006 he ran against corrupt incumbent Piombo in the primary--lost the primary, but Piombo was so weakened that he lost the general election. In 2008, McCloskey switched parties and supported Barack Obama."
http://www.pdaillinois.org/site/content/illinois-15-dr-gill-gets-key-endorsement