This term pre-dates the alt-right by decades. The term "dog whistle" was popularized by William Safire in 1988, who campaigned for Richard Nixon among other thi

This term pre-dates the alt-right by decades. The term "dog whistle" was popularized by William Safire in 1988, who campaigned for Richard Nixon among other things. It's historically understood to be a tool used primarily by social conservatives. "In 1981, former Republican Party strategist Lee Atwater, when giving an anonymous interview discussing former president Richard Nixon's Southern strategy, speculated that terms like "states' rights" were used for dog-whistling" https://en.wikipedia.org/wiki/Dog_whistle_(politics) https://en.wikipedia.org/wiki/Dog_whistle_(politics)