This incident can be used to illustrate a lot of core concepts, including government use of force; rule of law / limited government / constitutional government / securing rights; separation of powers; and the Fourth Amendment.
I think the entire letter would be useful when teaching the Presidency (e.g., the awesome responsibility of the office and the difference between the office and the person of the President), but I especially like the third point made by President Obama as a way to talk about fundamental principles of American government. And notice, also, the purposes of government Obama seems to assume he and Trump share in the first paragraph: “prosperity and security” are closely related to happiness/welfare and the securing of rights.
This could be useful for discussing the purposes of government (in general) and the Hobbesian / Lockean argument for why government may be necessary for protecting the right to life (in particular), but also how the government itself can be a source of threats to rights. (The people wanted security guards to protect them from the “violent / aggressive family,” but then the guards appear to have themselves become abusive.) I think this is also an excellent illustration of how one doesn’t have to assume that all or even most people are naturally violent in order to conclude that a well-ordered government can significantly reduce violence. In this case, one family was violent, but this led everyone else to hide, acquiesce, or fight for themselves in order to be secure from the instigators. Given enough time, and without security guards, the otherwise non-violent cruise members may have concluded that “the best defense is a good offense,” and thus begun to act even more violently towards the instigators. This kind of security logic is a significant part of the analyses of violence (and its decline) by Stephen Pinker in Better Angels of Our Nature and, to a lesser extent, by Daniel Deudney in Bounding Power.
I think a good discussion / activity to go with Chapter 1 of my textbook is to have students come up with a list of “public goods” and then ask if they are truly, strictly speaking, non-excludable. You don’t want to confuse them, but it might be worth thinking about the concept more closely and, it the process, ingrain in them the understanding that the technical definition of “public goods” means less than by what people often say are public goods. For example, a lot of things that most agree are socially beneficial (e.g., parks or roads) actually are excludable and therefore not actually “public goods.” We just choose not to exclude because we want “public” (i.e., universal) access. But it is only because of this strict definition of “public goods” as non-excludable goods that we can say that providing public goods is someting that all governments purport to do. Not every government makes a priority of providing public parks or universal literacy. But all governments claim to provide non-excludable goods like “national defense” and “order.”
Are people mostly self-interested egoists who are unlikely to help achieve common goals unless somehow forced or induced to do so by government or other powerful agencies? Although a lot of people (and the assumptions of traditional economics) suggest the answer is yes, there is reason to doubt this is so. Or, to be more precise, there is good reason to doubt it is true of all or even most people. For example, why does anyone voluntarily vote when there is essentially zero chance that doing so will promote the individual voter’s narrow self-interest? And why do people voluntarily recycle or work with others to help out a neighbor in need? At least some people seem to be motivated by a sense of social obligation or some motive(s) other than narrow egoistic self-interest.