the state. Finally, in June 1971, Peterson admitted he had made revenue miscalculations resulting in a $5 million deficit. The mistake opened the door to opponents of the other changes to unleash a barrage of criticism. As a result, when he sought a second term the next year, he won the Republican primary by 8% of the vote over former Lieutenant Governor David P. Buckson. In the general election, he was defeated by the Democratic former Lieutenant Governor Sherman W. Tribbitt after announcing an unexpected tax increase in the middle of the campaign. He left office with Delaware enjoying a budget surplus. Later career After leaving office, Nixon, impressed by Peterson's answers to Stans' questions, appointed Peterson as Chairman of the Council on Environmental Quality. Peterson served from 1973 to 1976, leading a taskforce on the elimination of chlorofluorocarbons and helping to shape environmental reviews as mandated by the National Environmental Policy Act. In November 1973, Peterson worked with then-Governor of New York Nelson Rockefeller to establish the Commission on Critical Choices for Americans. A keen bird watcher, Peterson took up the hobby after taking his son to the Everglades in 1954 and identified over 1,000 birds during his life. Peterson served as the president of the National Audubon Society from 1979 to 1985. He fought Ronald Reagan's attempts to weaken environmental regulations, pushed the society beyond its traditional remit into areas like energy policy, toxic waste and population control. He hired more scientists, started an environmental curriculum for school children and got Ted Turner to finance the TV series The World of Audubon, narrated by Robert Redford, amongst others. Peterson served as a visiting professor at Dartmouth College in 1985, Carleton College in 1986, and the University of Wisconsin–Madison in 1987. He also served as president of the International Council for Bird Preservation, as a principal officer in three international environmental organisations, worked for the United Nations on various activities and as chairman of the Center on the Long-Term Biological Consequences of Nuclear War, working with Carl Sagan, Paul R. Ehrlich and Peter Raven to employ scientists to inform world leaders of the dangers of nuclear weapons. In October 1996 Peterson switched his party affiliation to the Democratic Party, after endorsing Democrats in presidential elections since 1988. In 1971 the National Wildlife Federation gave Peterson the Conservationist of the Year award. In 1974, Peterson received the Charles Lathrop Parsons