Don't you like her then? I used to but I found that she was always trying to do down the girls in our tennis club who were not interested in joining her little clique. (Google)
If you go on doing everyone down like this, you will soon find yourself without a single friend. (Google)
It seems that many people, perhaps without even thinking about it, would rather do down the other player than cooperate with the other player to do down the banker. (BNC)