Possibility of finding specific Census data for a Congressional District

I figured I would ask here first rather than bothering the Census Bureau if I don't have to.

I am looking for specific population information for my US Congressional District. I'm not looking for the overall population of the district as I already have that. Rather, I am looking for the population for a specific area of the district versus the rest of the district. Is there a tool I can use on the Census Bureau's website that will allow me to do that?

Specifically, I'm looking for the population of the Illinois 2nd Congressional District north of a county border versus the population of the rest of the district south of that same border.