For the political term, see coattail effect

Coattail effect

The coattail effect is the tendency for a popular political party leader to attract votes for other candidates of the same party in an election...

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Riding coattails is a metaphor

Metaphor

A metaphor is a literary figure of speech that uses an image, story or tangible thing to represent a less tangible thing or some intangible quality or idea; e.g., "Her eyes were glistening jewels." Metaphor may also be used for any rhetorical figures of speech that achieve their effects via...

that refers to the way in which lower level or uninspiring celebrities can often reach stardom through their ties to another, more popular and successful celebrity. This can often be used as a generic phrase for anyone that hangs onto another person as they forge ahead, without effort from the hanger-on.