What is the origin of the idiom "lame duck" and when to use it?

The origin of the idiom "lame duck" phrase is uncertain, but it may be related to the idea of a bird that is injured or unable to fly, leaving it vulnerable to predators and unable to fend for itself. Over time, the phrase has come to be used more generally to describe any situation where someone or something is vulnerable or weakened, whether it be a political leader who is nearing the end of their term or a business that is struggling to stay afloat. The phrase can also be used to describe a person who is in need of help or support in order to succeed or achieve their goals.