Indeed, O.J. Simpson is more famous than any Cornell and Northwestern’s alumnus.
That said, USC hasn’t caught Cornell and Northwestern yet. Locations haven’t stopped Cornell, Penn, Dartmouth, Yale, Duke, etc. from being great. “Resources” mean different things to different folks, apparently it’s not endowment and certainly not endowment per capita to you. Regardless of resources and locations, I don’t think any school that axed its German program, starves its liberal arts departments, and focuses almost solely on trades/pre-professional programs would be among the best candidates to “break into the top echelons of higher education”.
OP,
For your major, Cornell and Northwestern likely have stronger departments. Graduate rankings may not be good proxy but when the gap is significant, it may be worth to take a closer look. Cornell and Northwestern are ranked around the 20th while USC’s is around 50th. The number of PoliSci faculty is considerably smaller at USC even though its undergraduate enrollment is the largest of the three (19,000 vs 14,400 at Cornell and 8,500 at Northwestern). You may want to research and compare the course offerings and selection.
USC has an interesting trial advocacy program while Northwestern has a legal studies program (an adjunct major through the lens of liberal arts). But in terms of preparation, this link from Cornell sums it up the best:
http://admissions.cornell.edu/learn/academics/prelaw
You may want to use it as your guide for your next four years. Go luck!