https://www.lewrockwell.com/lrc-blog/lees-prophecy/
Here is a website that provides some context for Lee's statement.
http://www.theimaginativeconservative.org/2014/08/acton-lee-conversation-liberty.html
It links to two letters between Lee and Lord Acton. Acton has been credited with saying, and I'm paraphrasing, 'power corrupts, absolute power corrupts absolutely'.