Among the many gray areas and judgment calls in law enforcement, disorderly conduct is one of the fuzziest. Just ask Harvard professor Henry Louis Gates Jr., arrested July 16 after yelling accusations of racism at an officer responding to a reported break-in at his home. Statutes outlining the misdemeanor are designed to help police maintain authority, and they are broadly worded; deciding what constitutes disorderly conduct is typically at an officer's discretion.
Disorderly conduct has its roots in the mid--19th century, when police officers needed a way to quell street brawls that erupted between immigrants and nativist groups, like the 1849...