The horse is a 'shoo-in' to win the race.
a 'shoo-in for' the tournament/job/award
(..) Let's just cut to the chase. Who do we have to sleep with for us to get in the show? Honey, you're so barking up the wrong tree right now. Really! lf you nail this, you're a shoo-in for the cover of Hamptons. Darlings! Where have you been? Megan! Don't! This is unacceptable. (..)2004 White Chicks