It's one of the left's favourite anti-capitalist soundbites and it is, in effect, explored by Arthur B Laffer and Stephen Moore in an article for The Wall Street Journal. Read it here.
The article makes the point that the income of America's poorest households is actually increasing, despite the claims of many, including Barack Obama.
It also contains this important quotation:
"Taking from the rich through much higher tax rates in order to help the poor and middle class makes no sense intellectually and has seldom worked in practice. Reducing rates, on the other hand, does increase the share of taxes paid by the highest income-earning group. For example, in 1981, when the highest tax rate on the rich was 70% and the top capital gains tax rate was close to 45%, the richest 1% of Americans paid 17% of total income taxes. In 2005, with a top income tax rate of 35% and capital gains at 15%, the richest 1% of Americans paid 39%."
