The text message arrived on Latrecia Breath’s phone while she was grocery shopping on a Sunday afternoon. "Please watch this," her friend urged. Ms. Breath, a sophomore majoring in broadcasting and electronic media at the University of Oklahoma, waited until she was in the parking lot before she clicked on the link. There, in her prune-colored Saturn, she watched the video that was rapidly engulfing the 27,000-student campus. Her university had become a flash point in the national conversation about race.