Amid a growing mound of Confederate flag cases, one unsettled legal issue in courts across the country is this: Can public schools ban the wearing of Dixie Outfitters and other Confederate T-shirts without running afoul of the First Amendment? The Dixie Outfitter shirts celebrate the Confederate flag—insofar as draping fuzzy baby bunnies, fuzzy puppies, and fuzzy duckies in flags could be said to constitute celebration. Schools in Florida, Georgia, Virginia, West Virginia, Kentucky, Michigan, and elsewhere have instituted bans, following complaints from parents and students who find them offensive. When Cherokee high school in Georgia banned the shirts last fall,...