stalking horse

noun4

1. •
   (old-fashioned) A horse used as cover by a hunter stalking game.
2. •
   A candidate put forward to serve a hidden, ulterior purpose in a political campaign, such as testing the field for another potential candidate by gauging voter sentiment or covertly helping another candidate by attracting voters away from a third candidate.

   • The Ministry had their candidate, a stalking-horse, useful only to receive the purely Ministerial votes. The votes, thus divided, gave no result. — 1842
3. •
   A person, thing, or expedient used in a deceptive manner, to achieve some hidden purpose.

   • Do you think my daughter […] fit for nothing but to be a stalking horse, to stand before you, while you take aim at my wife? — 1694
4. •
   the first bid on a bankrupt company, which sets the low bar for further bidding