@ucbalumnus, USC has long wanted to be at the point where it could compete for the same pool of students as Harvard and Stanford, and to do that USC needed to be able to offer free tuition to low-income students, just like Harvard and Stanford do.
The reason USC couldn’t do that earlier was because it didn’t have the endowment money to cover the costs. The best it could do was offer a small number of full-tuition merit scholarships, and a larger number of partial scholarships. But even after receiving the partial scholarships, many excellent students still couldn’t afford to go to USC. USC started a $6 billion fund-raising drive several years ago, and now it’s raised enough money to be able to offer free tuition.