In the drama category, Lost is competing with The Good Wife, Dexter, Mad Men, Breaking Bad, and dark horse True Blood.
Several years later I met George in New York while he was in the middle of his dark horse tour.
Today, though, the primary system makes it harder for a dark horse to make a splash.
Many conservatives are actively trolling for a dark horse to come in and rescue them from the current stable of 2012 candidates.
Oscar gurus even peg him as a dark horse for a Best Actor nod this year.
If he's a dark horse he might rook me at billiards or bridge.
Would any dark horse, at the last moment, enter to divide the interest?
But in the straight on the run home when all were in close order the dark horse Throwaway drew level, reached, outstripped her.
Heifetz, however, may be the dark horse in the modern fiddle sweepstakes.
Probably the girl had ridden the big, dark horse over this very road at night, alone.
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)