Bible-Thumping on Bourbon Street at Night Barred by Ordinance

"It shall be prohibited for any person or group of persons to loiter or congregate on Bourbon Street for the purpose of disseminating any social, political or religious message between the hours of sunset and sunrise." That is illegal, a completely and thoroughly illegal ordinance. Even the police have sense enough not to try to enforce it, according to the story. Why has New Orleans allowed their local politicians to believe they are above the law and able to ignore it when they create and pass their little ordinances?