Who coined the phrase perception is reality?

The phrase "perception is reality" has been attributed to political strategist Lee Atwater. Atwater is perhaps best known for his work on George H.W. Bush's campaign in the late 80's. He often used the phrase when talking about the importance of public relations to campaigning and was said to be "ahead of his time" with this idea. His promising consulting career was cut short when he died of a brain tumour at the age of 40. (http://www.pbs.org/wgbh/pages/frontline/atwater/etc/synopsis.html)