DREW, Miss. — The day of his high school graduation, like so many of the days before, began with chaos. Ruleville Central had pledged to lock its front doors an hour before the ceremony to prevent a crowd overflow, and Jadareous Davis was still at his grandmother’s home six miles up the road, time slipping away. Davis scanned through his mental checklist. Shoes? His older brother hadn’t yet swung by to drop off a pair. Bow tie? Maybe he could borrow one from a neighbor. Pants? Davis wasn’t even sure whether the dress code mandated black or brown, and he called a friend for help.