CAMBRIDGE, Mass. (AP) — A Justice Department inquiry into how race influences admissions at Harvard University has left selective colleges bracing for new scrutiny of practices that have helped boost diversity levels to new highs across the Ivy League.

Harvard and other top-tier colleges closely guard the inner workings of their admissions offices, but they defend approaches that consider an applicant's race among other factors as a way to bring a diverse mix of perspectives to campus. While the schools believe they are on firm legal ground, experts say the investigation could inspire new chal...