have legs

To have the ability to endure, stay relevant, or continue to maintain interest. Said of a concept, phenomenon, something discussed, etc. That theory really has legs—years later, most people still think that the wrong man was convicted. I didn't cheat on him, though! Gosh, that rumor really had legs, huh? I know bloodletting had legs for a long time, but thank goodness medicine has evolved beyond it now!

If an idea, plan, or story has legs, it is likely to be successful or to continue. Blucher was confident that his concept had legs, so he pressed Cooper for a meeting. In this instance the story might not have legs.