My English teachers strenuously denied it, but languages are not immutable. Centuries ago, Daniel Webster regularized the American spelling of various words ("center", "draft", etc). More recently, the public literally flipped the meaning of the word "literally" through chronic misuse.
Have there been successful, intentional campaigns to change the spelling and/or meaning of words within living memory? How or why did they succeed?
Changes that happened passively because people could care less [sic] about proper usage don't count.