have a down on someone/something
have a down on (someone or something)
To have or express negative or overly critical feelings toward someone or something. I don't know why you have a down on Robert—he's such a nice guy to everyone! Don't have a down on this vacation to your grandparents' farm. I know it's not very exotic, but we'll still have a great time!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
have a down on someone/somethingor
have a downer on someone/somethingBRITISH
If you have a down on someone or something or you have a downer on them, you do not like them or you disapprove of them. Snobs would have a down on a man with a south London accent. For some reason Jackie has always had a downer on me.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012