I saw it. I also listened to the Thomas Sowell video. Libertarians are not against the rule of law, but they are in favor of disobeying policies that violate fundamental rights or that undermine self-defense. Therefore, opinions wil vary with respect to sanctuary cities, even among libertarians. Privatizing the border is the best means to vet people and keep out criminals. I am not interested, however, in preventing the poor to come and work menial, farm or construction jobs. Thus, to the extent that sanctuary cities protect poor people, I do not care. However, I suspect that they also protect those that want to harm others, and then I do care. Eliminating sanctuary cities eliminates both good and bad. Best to start at the border and not have to worry about sanctuary cities.