The whole situation stinks because many do have more money than they can realistically ever spend, so your gut reaction is "make 'em pay" but on the other hand, some of them pay more taxes in a year than I do in my lifetime so they're already contributing an order of magnitude or more than I am.
The only thing that ever "makes sense" to me when trying to make it "fair" is a federal sales/service tax replacing the vast majority of taxes. This still isn't perfect but, at least to me, it makes way more sense than the way taxes currently work in the United States.