This makes it obvious that the Republican policies favor the rich, and actually hurt working Americans. By weakening unions and encouraging the outsourcing of American jobs (even to the point of giving tax breaks to companies that ship jobs overseas), the Republican policies have encouraged employers to stop sharing any rise in productivity with workers -- and that is exactly what those employers have done. Since 1980, employers have gobbled up all of the rise in productivity, and shared none of it with the employees responsible for that rise in productivity.
In previous years, the rise in productivity was shared between owners and workers. That contributed to a healthy and growing middle class, since the rising productivity truly did "lift all boats". The Republicans had claimed that their policy of funneling more money to the rich would benefit everyone since much of that money would trickle down to the workers. But nothing trickled down. Employers kept all of the increase, and left workers drowning in stagnation and inflation. This has resulted in a falling median wage and a disappearing middle class -- both ominous signs of an economy in trouble.