jump on the bandwagon

jump on the bandwagon
get aboard the bandwagon
get on the bandwagon

(join a new undertaking/enterprise at the beginning because it looks like being successful or because it's fashionable to do so) — вовремя вскочить в нужный вагон / поезд; примкнуть туда, где выгоднее; ~ вовремя подсуетиться и примкнуть туда, где выгоднее или безопаснее; примазаться (туда, где выгоднее)|| полит. bandwagon — массовая поддержка победившей стороны; массовый переход на сторону победителя (от band-wagon — фургон или грузовик с оркестром передвижного цирка и т. п.)

Example: “When I once became sure of one majority they tumbled over each other to get aboard the bandwagon”. (Theodore Roosevelt)

Example: I always question my decision to put my daughter in a progressive school which really could not be more different than what most other schools. It’s a scary thing to walk a path so few have taken. It’s something I grapple with almost daily – Will she thrive? Will she be globally competitive? Would it be easier to just jump back on the tried and tested traditional bandwagon?

Related
[know which side one's bread is buttered on]
know the way the wind blows/how the wind blows

[desert a sinking ship]
jump ship
You see, jumping on the bandwagon has pretty much always been in reference to politics; though today, many people use this term for many different things:

...Did you jump on the Harry Potter bandwagon? (I did, and I'm still there.)
...Did you jump on the Twilight bandwagon? (Nope, me neither)
...Did you jump on the Chargers bandwagon? (I may be hanging off the edge, but I'll always be there)

What bandwagons have you jumped on?

jump on the bandwagon (to profit from a craze; to join a trend; to do what everybody else is doing, whatever is popular. ) – приобщиться к чему-л. популярному, модному, распространяющемуся; начать делать что-л. на волне его популярности, успеха; ~ подсесть на что-л. популярное, модное; влиться в общую, нарастающую тенденцию; влиться в ряды почитатлей, фанатов, сторонников чего-л.

...After the incredible success of Cadbury's latest low-fat chocolate bar, Nestlé has jumped on the bandwagon, and released a low-fat version of Kit Kat.
...There had been so much hype about it, I didn't want to jump on the Harry Potter bandwagon just because everyone else was. ...
...It didn't take me long to jump on the Harry Potter bandwagon.
...I didn't jump on the Harry Potter bandwagon until the 4th book came out.

Related
keep up with the Jonses
стадное чувство