e existing republican
forms are continued by the States, they are guaranteed by the federal
Constitution. Whenever the States may choose to substitute other
republican forms, they have a right to do so, and to claim the federal
guaranty for the latter. The only restriction imposed on them is, that
they shall not exchange republican for antirepublican Constitutions;
a restriction which, it is presumed, will hardly be considered as a
grievance.

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. Insurrections in
a State will rarely induce a federal interposition, unless the number
concerned in them bear some proportion to the frien