I’ve tried to phrase it as “as much as we are taxed”. Some of them understand “tax billionaires” as “tax the hell out of them”. While people here may think that’s reasonable, how about we start with “as much as we are taxed”?

While I dont want to pay taxes any more than anyone else, I can’t really object to paying a higher rate than people with less income. But why aren’t wealthy people taxed at least as much?

Everyone (US) is at least somewhat familiar with different tax brackets even if they don’t understand them, so it should put it in better perspective that billionaires have at some point much lower effective tax rates than the rest of us, and it should be more clear how unfair that is. Not that it helps so far