The scene was similar in 1978 when Karol Wojtyla from Poland was elected on the eight ballot as a dark-horse candidate.
Another British-made film that enthralled crowds in Telluride is more of a dark-horse candidate.
A dark-horse candidate becomes likely only if one of the principal candidates withdraws in his favor.
in politics, 1842, an image from horse racing, in which dark is used in its figurative sense of "unknown."
Moonraker is called a "dark horse"; that is neither his sire nor dam is known. ["Pierce Egan's Book of Sports," London, 1832]
An unexpected winner. In politics, a dark horse is a candidate for office considered unlikely to receive his or her party's nomination, but who might be nominated if party leaders cannot agree on a better candidate.
: a dark-horse candidate/ dark-horse odds
A person or team, esp in sports or politics, that seems very unlikely to win but might nevertheless do so (1842+ fr horse racing)