In a town where talking is the main industry, the owners of a guide service say the city regulation for tour operators violates their First Amendment free-speech rights.
The District of Columbia government says the occupational licensing is a routine requirement that in no way restricts what tour operators may say as they guide tourists around town.
But the lawsuit against the district by guide company owners Tonia Edwards and Bill Main raises a question: Should the guided tours their firm makes to Washington's landmarks aboard battery-powered Segways be regulated at all?
Judge Janice Rogers Brown, appointed to the appeals court by President George W. Bush, expressed doubts about whether the tour guide regulations were really necessary.
Judge Robert Wilkins, a recent appointee of President Barack Obama, focused on the fact that tour bus drivers who just play audio recordings as they drive tourists around town aren't licensed under the regulation, but would be if they talk face to face with their passengers.
The city licensing requirement includes passing a multiple-choice test about the District of Columbia and its tourist attractions. The purpose, according to the city, is ensuring that prospective guides are who they say they are and have at least a minimal grasp of the city's history and geography.
"How does being able to pass an exam about points of historical interest have any relationship to whether or not you're going to treat people carefully, take care of them, not abandon them?" Brown asked.
The licensing process in Washington itself has a long history, driven primarily by the need to protect the safety of tour-group members. The law was first enacted more than a century ago, and newspaper stories from the time say tourists were being intimidated and harassed by unlicensed guides.
A federal judge last year found that the licensing requirement does not significantly infringe speech.