on the bandwagon, to get/climb/hop

climb on the bandwagon

To join or follow something once it is successful or popular. I can't stand these people who just climb on the bandwagon after a win. Where were they last year when the team was terrible? A: "I thought your mom hated that candidate." B: "Well, he's the president now, so she's climbed on the bandwagon."
See also: bandwagon, climb, on

get on the bandwagon

To join or follow something once it is successful or popular. I can't stand these people who just get on the bandwagon after a win. Where were they last year when the team was terrible? A: "I thought your mom hated that candidate." B: "Well, he's the president now, so she decided to get on the bandwagon."
See also: bandwagon, get, on

on the bandwagon, to get/climb/hop

To join the cause, movement, or party. The original bandwagon was a horse-drawn wagon bearing a brass band, used in a circus parade. In the second half of the nineteenth century such wagons began to be used in political campaigns as well, accompanying a candidate on speech-making tours. During William Jennings Bryan’s presidential campaign of 1900 the term began to be extended to mean supporting the movement itself. It also was used in Britain: “The Mirror . . . does not jump on bandwagons . . . it isn’t, never has been, and never will be a tin can tied to a political party’s tail” (Daily Mirror, 1966; cited by William Safire).
See also: climb, get, hop, on