The caste debate is always complex and is most of the times based on the "Social location" of individual who is part of the discussion in my exprience.
"If I were a SC/ST" is a good way of looking at the situation. Sometimes even I thought from that point. I realised by travelling across Karnataka that nobody else
can feel the "Untouchability" , we might maximum understand but not get the mental state. When a untouchable is given water from a height the feelings that
generate can imagination generate it?.
I think Romilla thappar . D.D.Khosambi, Ambedkar Irfan Habib and several others have writen on how Historically caste developed. There are discriminations in several instittutions in the society.
Only religion in which structured Heirarchical based discrimination is part of Hinduism. Today caste is no more just based on "Division of Labour" the untouchabilty practices have changed. So I prefer not going into it.I would like to point to a study done by Sharmila Rege, Thorat which came in tehelka(i have lost the link). It was more of an experiment, they sent some sample set of resumes to different companies with names indicating caste. One will be shocked to see who got the interview calls.
I do not want to make any point I am just trying to have a understanding of caste system's expression in todays world. There is a nice film by Stalin called "India untouched" I was shocked to see what it shows.