Again this is about something you obviously don't understand - progressive taxation. Every nation on earth collects taxes has some form of progressive taxation. I know you don't realize this because FOXNews never talks about it - but it's true.
The idea is that someone with millions in spending money can afford to shoulder a little more of the burden than someone whose every disposable dollar goes towards necessities. The other part of the equation is that rich people have much much more to lose this country were to descend into chaos will be invaded by another country. In general peasants just have to answer to a new master, rich people lose everything.