This article points out some interesting points:

People with low education gets replaced by machines
Automatic machinery such as ATM, automated customer service lines, self-serve gas, online bill paying, automated package tracking removes the need for people to do these tedious tasks. And these tasks were normally done by people with low education.

The numbers
quote article: “For college-educated men, the median weekly wage rose 20 percent in real purchasing power from 1979 to 2002. Women with college degrees did even better — up 34 percent”. For high school drop outs: “Down 27 percent — meaning that over a 23-year period of relatively robust economic growth, low-skilled workers have seen more than a quarter of their purchasing power disappear and are now significantly worse off than they were in 1979″.

quote article: “Technology replaces far, far more low-skill jobs than foreign workers do”.