From Longman Dictionary of Contemporary Englishbe down on somebody/somethingbe down on somebody/somethinginformalAGAINST/OPPOSE to have a severe attitude towards someone or something, especially when this is unfair Why is Mark so down on her at the moment? → down
Examples from the Corpus
be down on somebody/something• Copper producers were down on a drop in copper prices.• At the half-year stage profits are expected to be down on last year - around £35m against £39m.• It wasn't that money was being stolen or sneaked - everything was down on paper.• Constable Collins liked shrimp and often bought a tub of them when he was down on the Front.• Ten minutes later I was down on the private beach.• He was down on the shore, a shadow edged with silver light, combing the tide line.• Families that were down on their luck could get a small loan, food, a job referral.