Keeping the wage up is influenced by a host of variables. The rich will always get richer on average, they have more resources to invest, 10% return on 1000 is going to be more than 10% on 100 to put it in real simple terms. The middle class also faces competition from workers overseas in the global economy. You can't expect to keep getting paid 10 times more for doing the same job. One thing would help is to address the illegal problem, here in Boston the federal government just busted a shop that was hiring illegals to make backpacks for US army. They rounded up about 300 illegals and is in the process of deporting them. Our new Governor Deval is calling the deportation inhumane, of course he is not worried about the 300 jobs that was taken away from Americans or legal immigrants.
The bottom 30% don't pay taxes. The bottom 20% even get earned in come back. Those numbers are WAG's but you get the idea.