: someone or something that is used to hide a true purpose; especially : a candidate for a political office or position who has no real chance of winning but is being used by a political party to weaken the support for an opposing party, to find out if another candidate might be successful, etc.
Full Definition of STALKING HORSE
: a horse or a figure like a horse behind which a hunter stalks game
: something used to mask a purpose
: a candidate put forward to divide the opposition or to conceal someone's real candidacy