Or, you could just tax all the s*** that rich people spend money on. Determine an "average" family car (in my mind it's a Camry) and slap a Federal excise tax on every dollar above the price of that car. So if a new Camry costs $25K and you buy a luxury car for $65K, you pay tax on $40K. Tax property above a certain value, jewelry, hotels.
You can create excise taxes that are paid almost entirely by the rich, a little bit by the middle class, and none by the poor.
The rich people have less reason to b****, since they are choosing to make these purchases so you aren't just "taking their money". There are also less loopholes than income tax (though I'm sure people will find some).