An academy instructor once suggested that a good way to avoid accusations of bias during a traffic stop was to decide whether to issue a ticket or offer a warning before contacting the driver. He reasoned that this simple rule would ensure that any enforcement action would be based on the violation and not on appearance, attitude, race, gender, or anything else. The instructor may have been more of a constitutional scholar than anyone knew.

The U.S. courts have not given specific guidance as to whether, or to what extent, statements or attitude may be considered when deciding on the appropriate enforcement action. Taking enforcement action against a vulgar and disrespectful person does not, in and of itself, violate the First Amendment. However, punishing or retaliating against someone for engaging in free speech by issuing a citation, making an arrest, or taking another enforcement action, can violate the citizen’s rights—even if probable cause exists.