The Collaborative International Dictionary of English v.0.48:

Nominee \Nom`i*nee"\, n. [See Nominate, and -ee.]
   A person named, or designated, by another, to any office,
   duty, or position; one nominated, or proposed, by others for
   office or for election to office. One remains a nominee until
   one has been elected or has assumed the office.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

nominee
    n 1: a politician who is running for public office [syn:
         campaigner, candidate, nominee]

The Devil's Dictionary (1881-1906):

NOMINEE, n.  A modest gentleman shrinking from the distinction of
private life and diligently seeking the honorable obscurity of public
office.