WASHINGTON, Aug. 9 (UPI) -- Two former heads of the Environmental Protection Agency who served in three Republican administrations signed a joint letter saying they support Hillary Clinton for president because Donald Trump demonstrated a "profound ignorance" of environmental issues.
The former administrators, William Ruckelshaus and William Reilly, said Clinton, by contrast, is "committed to reasonable, science-based policy."
Ruckelshaus was the first EPA administrator when the agency was founded under President Richard Nixon. He later returned to that post under President Ronald Reagan. Reilly served as EPA administrator under President George H.W. Bush.
The two men wrote an open letter, stating Trump has shown "a profound ignorance of science and of the public health issues embodied in our environmental laws."
"That Trump would call climate change a hoax -- the singular health and environmental threat to the world today -- flies in the face of overwhelming international science," the pair wrote.
Reilly has also served as president of the World Wildlife Fund and was appointed in 2010 by Obama to serve as co-chair of the National Commission on the BP Deepwater Horizon oil spill.
The former EPA leaders are the latest in a string of Republican bureaucrats and elected officials who have announced they will not support the party's 2016 nominee. Fifty national security experts from former Republican administrations signed a letter recently saying they would not support Trump, calling him "reckless." That group included the first two secretaries of Homeland Security under George W. Bush, Tom Ridge and Michael Chertoff, the co-author of the PATRIOT Act.
Collins said she had hoped Trump would tone down his rhetoric, but in the weeks since accepting the nomination, she said he has shown no willingness to do so.
"The unpleasant reality that I have had to accept is that there will be no 'new' Donald Trump, just the same candidate who will slash and burn and trample anything and anyone he perceives as being in his way or an easy scapegoat," Collins said.