I would like to see the actual numbers of people in those stats. Since O’Reilly has 33% more viewers, that additional amount could account for the portion of lower income/education folks. I bet the gap looks significantly smaller if you look at true numbers rather than percentage of all viewers. Further, O’Reilly probably has significantly more retired people watching his show. These people probably have a lower income than employed people. Additionally, postgraduate education has become much more important in the last 20 years and older generations probably have a lower percentage of postgraduate degrees (my very smart grandfather did just fine with an eighth grade education).
I would like to see these statistics broken down into pure numbers and by age. They might tell a totally different tale.