A very easy target: “His arguments were so simple, she was able to knock them down like sitting ducks.” The term comes from hunting, where it is much easier to hit ducks when they are sitting on the water than when they are in flight.
|a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison.|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
sitting duck definition