Courts have held that burning the American flag is protected symbolic speech under Texas v. Johnson (1989) and U.S. v. Eichman (1990), limiting what presidents and DOJ can do to punish desecration. Executive pushes that direct agencies to prosecute flag burning often collide with those rulings and typically fail once challenged.
Recent examples include attempts to charge protesters under executive guidance during Trump-era flag-burning crackdowns, which were dropped when prosecutors recognized the binding Supreme Court precedent.