Once upon a time, the US economy grew and everybody shared the fruits of that growth...
That changed around the time an actor got elected to the White House and unleashed a wave of "freedom" to make more money. Some did.
(hat tip to rdf for the link to the Office for Social Justice which provides the above graphs, and to peeder and mikepridmore for the links below to EPI.)
The tax system, which might have been used to redistribute that wealth around somewhat, only makes things worse nowadays:
In recent years, median income (i.e. half earn more and half earn less; in an unequal economy, median wages are lower than the average) has stagnated (because of inflation), except in the boom years of the second Clinton mandate:
(from this pdf presentation from epinet)
And ever since, the situation has been really bad, with the Bush recession being by far the worst on record as far as income and wages are concerned (and note that the graph below reflects the average, and not the median, which has fared even worse):
(from this pdf paper from epinet)
Inequality has been rising for the past 25 years, and is getting worse. It's time to take care of the lower incomes and not of the higher income groups. An increase in the minimum wage would be a reasonable start.