In Federalist No. 14, Madison returns to the helm to answer objections to the proposed constitution from extent of territory.
The first thing Madison notes is that, in a democracy, the people meet and exercise the government in person; in a republic, they assemble and administer it by their representatives and agents. A democracy, consequently, will be confined to a small spot. A republic may be extended over a large region. Hence, any objections to the loss of democracy should be refuted by this statement alone as a republic can extend government by the people over a much larger territory.
Then he goes on to note that, in the first place it is to be remembered that the general government is not to be charged with the whole power of making and administering laws. Its jurisdiction is limited to certain enumerated objects, which concern all the members of the republic,
but which are not to be attained by the separate provisions of any. The subordinate governments, which can extend their care to all those other subjects which can be separately provided for, will retain their due authority and activity. Hence, any objections to the government amassing too much power should be dealt with as the government gets no more power than the people give it.
In addition, he notes that if some distant states should derive less benefit, therefore, from the Union in some respects than the less distant States, they will derive greater benefit from it in other respects, and thus the proper equilibrium will be maintained throughout. So while some states may have to send representatives further than others to take their seat on the government, they will benefit from the greater protection offered by the union.
So while objections can be made as to the potential strength of a union, versus a loose confederacy, they can also be countered. In this piece, Madison echoes Hamilton and again conveys the argument that united we stand and divided we fall.