According to some sources, lame duck made its way into politics from the financial district. Early records trace it back to the 18th-century London Stock Exchange, where it was used to refer to a stockjobber or dealer who was unable to meet his financial obligations, so that he was forced, as one etymologist put it, to waddle out of the alley like a lame duck.

Lame duck then made its web-footed way from finances into business. In British English, a lame duck refers to a corporation or other commercial interest that can't survive without government support.

Unlike these ducks that are labeled lame either because of inherent weakness or because they fall behind in achievement or ability, the political lame duck is hobbled by something else: his or her impending (and looming) replacement. Sometimes these lame ducks have been defeated at the polls and are awaiting the end of their term. Other times they are victims of their own successes. That's just the case with a two-term, lame duck president who paddles in place and awaits his next opportunity to make a splash.