Flagging does, in fact push posts down. I believe the amount is proportional to the flagger's karma. Psychologically, the UI seems intended to separate "I don'

Flagging does, in fact push posts down. I believe the amount is proportional to the flagger's karma. Psychologically, the UI seems intended to separate "I don't like this" from "I think this content is detrimental to the site". This communicates that users should not attempt to punish links they simply dislike, but may do so with comments.