Is the playing field leveled in the classroom?

Writing my 4th paper on how school doesn't level the playing field. I see that school can be a hinderance or a tool based on one's class status. People from the upper class and middle class have better access to resources such as new text books, tutoring, advanced technology. This factor gives people from the upper and middle classes an upper leg in getting a formal education (college degree). People from lower class tend to be forced to worry about certain obstacles like finaces, etc. before they can even think about excelling in the class room. Moreover schools want to standarize every student's ability and compare each student based on annual income instead of true potential making the chances of a student from the lower class to get into a top college slimmer than a student from the upper class.