Question

Dark-Horse Candidate a contestant about whom little is known and who wins unexpectedly

Accepted Answer

Everyone was surprised when Pedro won the election because he was a dark-horse candidate. There are at least three possible origins to this idiom and all come from horse racing in the early 1800s. The first is that a dark horse was a fast runner whose speed was kept secret ("dark") until the race started, and who, to everyone's surprise, won. The second is that an owner of a fast horse sometimes dyed its hair black as a disguise before a big race. The third is that a certain American horse trader fooled people by disguising his fast black stallion as an ordinary saddle horse. He rode the horse into town, arranged for a race, took bets on it, and always won. The term was introduced into American politics with the surprise win of President James Polk in 1844.

Idiom	Dark-Horse Candidate
Example	Everyone was surprised when Pedro won the election because he was a dark-horse candidate.
Meaning	a contestant about whom little is known and who wins unexpectedly
Origin	There are at least three possible origins to this idiom and all come from horse racing in the early 1800s. The first is that a dark horse was a fast runner whose speed was kept secret ("dark") until the race started, and who, to everyone's surprise, won. The second is that an owner of a fast horse sometimes dyed its hair black as a disguise before a big race. The third is that a certain American horse trader fooled people by disguising his fast black stallion as an ordinary saddle horse. He rode the horse into town, arranged for a race, took bets on it, and always won. The term was introduced into American politics with the surprise win of President James Polk in 1844.

Horse Fast Dark Horse Candidate Won Black American Surprised