This line comes from the first 2020 United States presidential debate on 29 September 2020, when Donald Trump was asked to condemn far-right groups and responded by naming the Proud Boys and telling them to stand back and stand by. The phrase was clipped and shared widely across social media and news coverage the same night, quickly becoming a meme and a shorthand for a tense warning. It remains in use because the original moment is so widely recognised and the wording works as a dramatic cue in political edits and reaction videos.