Short, simple, emotive phrases that are easy to remember are a powerful form of propaganda. Not unlike a viral tweet or meme, a memorable slogan can easily stick in the minds of the public. Repetition of the slogan through mass distribution spreads and legitimizes the message.
Like most tools used in propaganda, slogans are engineered to elicit an emotional response. Throughout the 20th century, slogans were utilized to quickly promote ideas and motivate or dissuade action.