Back in 1980, under President Reagan, the Republicans initiated their "trickle-down" economic policy. The idea was that by making things economically better for the richest Americans, everyone would benefit (because much of the new money received by the rich would trickle down to everyone else in the form of new jobs and higher wages).
That didn't happen. Wages for most became stagnant, while income for the rich skyrocketed -- and none of the money trickled down (but just fattened the bank accounts of the rich). The chart above (from the New York Times) compares income growth in 1980 with growth in 2014. Note that only the top 5% have benefitted from the GOP's economics (and most of the income growth is limited to the top 1%). The bottom 95% have seen their share of income growth go down.
In other words, the "trickle-down" policy has been great for the rich, but has hurt everyone else. Are the Republicans ready to admit they were wrong, and return to a saner and fairer economic policy? Not at all. The current Republican Congress seems convinced they just haven't given the rich enough, and if they give them even more (through massive new tax cuts) then the policy will begin to work for everyone.
It won't, and it shows just who the Republicans really care about -- the rich and the corporations, and no one else. It's just one more reason why the Republicans must be voted out of power next year.