Punching down
To insult or abuse someone for being lesser in some way (usually objectively) than yourself.
Stop being an asshole and punching down just because you're better at sports.
punching down
For someone of higher rank, power, status, and position to engage someone of much lesser and/or inferior rank, status, power, and position in debate and/or argument. Not limited to just status, power, position, and rank but can and often do include intellect, capability, competence, and acumen.
Oprah Winfrey didn't dignify Donald Trump's attack on her with a response because she doesn't believe in punching down.
Punching Down
Making a choice that is beneath your personal level of acceptance or standard.
"Dog, ol' girl wants to get with me but I ain't feelin' her look. I ain't punching down just to get some pussy."
"My job wants me to take a pay cut for the same amount of work? Oh no, I am not punching down-fuck that I'm out!!!"
"My job wants me to take a pay cut for the same amount of work? Oh no, I am not punching down-fuck that I'm out!!!"