on someone's coattails

on (one's) coattails

Benefiting from someone else's success; using someone else's success as a means to achieve one's own. Everyone knows you've been on the governor's coattails these last two years, but once her term ends, you'll be on your own. A: "I can't believe Jonathan got his paper published in that prestigious journal." B: "Oh, it's only because he's on his professor's coattails."
See also: coattail, on

on someone's coattails

Also, on the coattails of. Owing to another person's popularity or merits. For example, He won the cabinet post by hanging on the senator's coattails, or He was elected to office on the coattails of the governor. This expression, with its graphic image, dates from the mid-1800s, when coats with tails were in fashion.
See also: coattail, on