Thanks for all of the insightful replies.
I understand about the contamination aspect. But let me pose the following:
I buy fresh chicken from the market on Mon.
Come home, make dinner, which includes rolling that chicken in breadcrumbs.
Yes, some of the unused breadcrumbs come into contact with the raw chicken.
I put the unused bc in a sealed tupperware container, and place the container in the fridge.
I also place the unused chicken (unfloured and unbreaded) in the fridge.
Wed eve, I make dinner, which consists of the chicken purchased on Mon., and the unused bc.
The Q is - why would this be bad? If the chicken is still good two days later, why would the bc not be?
I can't disagree with those who say "why take a chance"... and sure, for the amount of bc that were left over, we are not talking an exorbitant amount of money. But at the same time, I do not like to waste food. So, is there a reason that bc used on Mon would not be ok to use on Wed?