A protection against invasion is due from every society to the parts composing it. The latitude of the expression here used seems to secure each State, not only against foreign hostility, but against ambitious or vindictive enterprises of its more powerful neighbors. The history, both of ancient and modern confederacies, proves that the weaker members of the union ought not to be insensible to the policy of this article. Protection against domestic violence is added with equal propriety. It has been remarked, that even among the Swiss cantons, which, properly speaking, are not under one government, provision is made for this object; and the history of that league informs us that mutual aid is frequently claimed and afforded; and as well by the most democratic, as the other cantons. A recent and well-known event among ourselves has warned us to be prepared for emergencies of a like nature. At first view, it might seem not to square with the republican theory, to suppose, either that a majority have not the right, or that a minority will have the force, to subvert a government; and consequently, that the federal interposition can never be required, but when it would be improper. But theoretic reasoning, in this as in most other cases, must be qualified by the lessons of practice. Why may not illicit combinations, for purposes of violence, be formed as well by a majority of a State, especially a small State as by a majority of a county, or a district of the same State; and if the authority of the State ought, in the latter case, to protect the local magistracy, ought not the federal authority, in the former, to support the State authority? Besides, there are certain parts of the State constitutions which are so interwoven with the federal Constitution, that a violent blow cannot be given to the one without communicating the wound to the other.