It's not a harmful bug, but it's certainly not behavior users will appreciate. I could imagine a new user not understanding the one man, one vote property of th

It's not a harmful bug, but it's certainly not behavior users will appreciate. I could imagine a new user not understanding the one man, one vote property of the system, then being confused later when the votes seem not to have gone through. Adding the visual effect of idempotency on the frontend is probably a two-second fix, anyway.