Since last week we talked about elephants in rooms being ignored, we decided that this week’s idiom should also be animal-related. This time, the subject is the expression dark horse. This concept is used in different contexts, particularly in politics, although the term originated from horse racing. In that particular context, a dark horse was one whose racing abilities were not quite clear to gamblers but one which ended up coming first in a race.
In that same vein, when a candidate in an election is referred to as being a dark horse, it means that, even though the person entered the race as a lesser known candidate, they may win said election due to experiencing unexpected popularity. A ‘dark horse’ is not limited to politics and does not always exclusively apply to the context of a contest or competition.
For instance, when a background character in a given piece of media becomes unexpectedly popular within fandom—at times even more popular than the main characters—they are referred to as being a dark horse. Sometimes it is the creators themselves who end up liking a background character so much, that they promote them to the main ensemble. One such example is the character of the Janitor in the TV show Scrubs who was meant to be a one-time role in the show’s pilot. The creator of the series enjoyed the Janitor enough to keep him for the rest of the series.