Definitely. There was a news segment I saw recently and a number of the top earners are paying a smaller percentage than many of us (i.e. Warren Buffett).
When super-wealthy, like Warren Buffett, proclaim that they are spending less percentage-wise than their staff is somewhat misleading... For starters, they are usually able to write-off more for charitable contributions, but like a previous post pointed out, they are planning to give to charity anyways; financially it would make no sense to spend more money on charities than you'd get to write-off in taxes. If the charities are not getting their funding thru private sources, they will either cease to exist or will try drawing from the public sector, thereby increasing government spending (and the need to tax the "rich" even more). Also, the super-wealthy save money and later can live off of their savings. So if the
income taxes get too high, they can stop receiving any
income from their business and just live off of the savings. For example, there's a Google exec that boasted that he was receiving an income of 1-cent (he could do this, because he's just live off of the interest and dividends from his stocks in Google). Remember that when we are talking about taxes, it is usually income tax that we are talking about; I the the "Buffett Rule" would be more aptly named if it was targeting dividend taxes which is where Buffett is getting most of his money from.