Former Richard Nixon challenger Pete McCloskey dies at 96

The former California Rep. Pete McCloskey, who tried to challenge the late President Richard Nixon for the presidency in 1972, died at the age of 96 on Wednesday.

McCloskey, who served in the House as a Republican for 15 years, died at his home in Yolo County, California, from congestive heart failure, according to Mercury News.

The anti-war Republican-turned-Democrat also co-wrote the Endangered Species Act, and co-founded Earth Day. He is survived by his wife, Helen, and four children: Nancy, Peter, John and Kathleen.

McCloskey spent most of his life as a Republican, but changed parties in 2007, citing disillusionment with the party due to multiple scandals in former President George W. Bush's administration, per the Associated Press. Although he was primarily a Republican, he was considered left-leaning due to his pro-environment, and anti-war stance.

The former congressman was also the first to demand Nixon's impeachment after the Watergate scandal.

McCloskey's legacy is primarily centered on the Endangered Species Act, which protects animal species that are endanger of going extinct. The former lawmaker co-wrote the legislation in 1973, and claimed it helped change the world.

"On that day, the world changed," McCloskey said in 2008. "Suddenly, everybody was an environmentalist. My Republican colleagues started asking me for copies of old speeches I had given on water and air quality."

McCloskey has been praised as a man who put principle before politics, and considered himself a conservative "in the mold of Teddy Roosevelt." He is also a decorated Korean War veteran, who served as a combat marine. 

“He stood for everyone without a voice, and was especially passionate about our environment — he was afraid of nothing or anyone who sought to take advantage of another,” Joe Cotchett, his law partner since 2004, said in a statement. “He was the epitome of a leader, as demonstrated throughout his entire life.”