come down on
Also, come down upon.
Also, come down hard on. Punish or reprimand severely. For example, My professor is going to come down on me for not completing the paper, or The judge promised to come down hard on drug dealers. [Early 1600s] Also see like a ton of bricks.
Oppose, voice one's opposition, as in The President came down on the new budget cuts, promising to veto them. [late 1800s]
come down on the side of. Make a choice or decision in favor of, plump for, as in I'll come down on the side of those who are needy.