(politics) the consequence of one popular candidate in an election drawing votes for other members of the same party; "he counted on the coattails effect to win him the election
Riding coattails is a metaphor 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
immediately following or undeservedly benefiting from; "the CEO resigned on the coattails of the scandal"; "he was elected on his predecessor's coattails