favorite (top choice) for the championship (favourite); best bet for the title
proposed site; site chosen
most likely contender; prime candidate; top prospect; leading candidate
major contender; strong (leading) candidate; front runner
rival candidate; opposing candidate
candidate for vice-president; running mate (US)
ever unsuccessful candidate; persistent candidate
candidate for assassination
party appointee in a safe constituency; (lit.) parachute candidate
(pharmaceutical) candidate compound