Source: acivilamericandebate .com; "A 30 year growth of Income Inequality. Posted on April 10, 2011
"In 1928, the top 1% was taking in 23.9% of earnings. With that degree of inequality, there was not enough income and wealth and available within the rest of the population (the bottom 99%) to sustain prosperity. In 1976, just before the Reagan Revolution, the top 1% was taking in 8.9%.
The top tax rate becomes too low to maintain stable income inequality.
With the lowering of the top income tax rate in 1981, the percentage of income of both the top 10% and the top 1% began to increase sharply, and by 1986 their shares of income were 40% and 15%, respectively. At the beginning of the Clinton Administration, another sharp increase began, and the top 10% moved to over 47% by 1998 and the top 1% rose to 22%. By 2007, the figure for the top 10% was back 50%, where it had peaked 80 years earlier. And the top 1%, similarly, was back near the 1928 level, at 23.5%.
Note that “[t]he same pattern held for the richest one-tenth of 1% (representing about 13,000 households in 2007): Their share of total income also peaked in 1928 and 2007, at over 11%.” 
So here was the situation in 2007:
Percentile % of Total Income
Top 0.1% 11%
Top 1 % 23.5%
Top 10% 50%
Let’s reflect on these numbers: The top 10% has as much income as everybody else; and one-half of what comes in to the top 10% goes to the top 1%. And the income of the top 1% is heavily concentrated at the very top.
In effect there are increasingly two economies, a wealthy “top” economy doing very well, and a “bottom” economy for roughly the bottom 99% facing income stagnation, with dwindling wealth and resources."
"Robert Reich puts it this way:
The wages of the typical American hardly increased in the three decades leading up to the Crash of 2008, considering inflation. In the 2002, they actually dropped. According to the Census Bureau, in 2007 a male worker earning the median male wage (that is, smack in the middle, with as many men earning more than he did as earning less) took home just over $45,000. Considering inflation, this was less than the typical male worker earned thirty years before. * * * But the American economy was much larger in 2007 than it was 30 years before. If those gains had been divided equally among Americans, the typical American would be more than 60 percent better off than he actually was by 2007. "