1.  dark horse(n = noun.person) Array - a political candidate who is not well known but could win unexpectedly; Array
is a kind of campaigner, candidate, nominee

2.  dark horse(n = noun.animal) Array - a racehorse about which little is known; Array
is a kind of bangtail, race horse, racehorse

N  politics, political science, candidacy, campaign, campaigning, electioneering, partisanship, ideology, factionalism, election, poll, ballot, vote, referendum, recall, initiative, voice, suffrage, plumper, cumulative vote, plebiscitum, plebiscite, vox populi, electioneering, voting, elective franchise, straight ticket, opinion poll, popularity poll, issue, opinion, stand, position, program, platform, party line, democracy, republicanism, communism, statism, state socialism, socialism, conservatism, toryism, liberalism, whigism, theocracy, constitutional monarchy, party, Democratic Party, Republican Party, Socialist Party, Communist Party, Federalist Party, Bull Moose Party, Abolitionist Party, Christian Democratic Party, Social Democratic Party, National Socialist Worker's Party, Nazi Party, Liberal Party, Labor Party, Conservative Party, ticket, slate, politician activist, candidate, aspirant, hopeful, office-seeker, front- runner, dark horse, long shot, shoo-in, supporter, backer, political worker, campaign worker, lobbyist, contributor, party hack, ward heeler, regional candidate, favorite son, running mate, stalking horse, perpetual candidate, political animal, political contribution, campaign contribution, political action committee, PAC, political district, electoral division, electoral district, bailiwick, electorate, constituents, get-out-the-vote campaign, political education, negative campaigning, dirty politics, smear campaign, also-ran, loser, has-been, office holder, official, occupant of a position, public servant, incumbent, winner, political, partisan, Money is the mother's milk of politics.

american saddle horse, cart horse, cavalry horse, charley horse, coach horse, crazy horse, dark, dark adaptation, dark ages, dark blue, dark bread, dark chocolate, dark cloud, dark comedy, dark field illumination, dark glasses, dark ground illumination, dark lantern, dark matter, dark meat, dark red, dawn horse, draft horse, draught horse, dray horse, farm horse, female horse, gift horse, grope in the dark, gymnastic horse, harness horse, high horse, horse, horse around, horse balm, horse barn, horse bean, horse blanket, horse botfly, horse breeding, horse brier, horse cart, horse cassia, horse cavalry, horse chestnut, horse doctor, horse fancier, horse fly, horse gentian, horse grain, horse gram, horse guards, horse latitude, horse latitudes, horse mackerel, horse manure, horse mushroom, horse nettle, horse of the wood, horse opera, horse parsley, horse pistol, horse power, horse race, horse racing, horse radish, horse sense, horse show, horse thistle, horse tick, horse trade, horse trader, horse trading, horse wrangler, in the dark, iron horse, long horse, male horse, one horse, pack horse, plantation walking horse, plough horse, plow horse, pole horse, pommel horse, post horse, przevalski's horse, przewalski's horse, quarter horse, race horse, riding horse, river horse, rocking horse, saddle horse, sea horse, shire horse, side horse, stalking horse, stick horse, tennessee walking horse, three-year-old horse, towel horse, trojan horse, trotting horse, two-year-old horse, vaulting horse, walking horse, war horse, wheel horse, white horse, white horse nettle, wild horse, wooden horse