"The phrase 'enemy from within' has an ugly history. It was famously used by Senator Joseph McCarthy in a 1950 speech: 'When a great democracy is destroyed, it will not be from enemies from without, but rather because of enemies from within.' (McCarthy attributed the quote to 'one of our outstanding historical figures,' but that claim appears to be apocryphal.)"
~ Judd Legum, Rebecca Crosby, and Noel Sims