Two important conclusions

The first is, that the Convention must have enjoyed in a very singular degree, an exemption from the pestilential influence of party animosities, the diseases most incident to deliberative bodies, and most apt to contaminate their proceedings. The second conclusion is, that all of the deputations composing the Convention, were either satisfactorily accommodated by the final act; or were induced to accede to it, by a deep conviction of sacrificing private opinions and partial interests to the public good, and by a despair of seeing this necessity diminished by delays or by new experiments.

James Madison in Federalist No. 37

Being subjected to the laws they pass, too

The House of Representatives … can make no law which will not have its full operation on themselves and their friends, as well as on the great mass of society. This has always been deemed one of the strongest bonds by which human policy can connect the rulers and the people together. It creates between them that communion of interests and sympathy of sentiments of which few governments have furnished examples; but without which every government degenerates into tyranny.

James Madison in Federalist No. 57

Keeping justice in mind

Justice is the end [goal] of government. It is the end of civil society. It ever has been, and ever will be pursued, until it be obtained, or until liberty be lost in the pursuit. In a society under the forms of which the stronger faction can readily unite and oppress the weaker, anarchy may as truly be said to reign, as in a state of nature where the weaker individual is not secured against the violence of the stronger …

James Madison in Federalist No. 51

National or state identity first?

If, therefore, … the people should in the future become more partial to the federal than to the State governments, the change can only result, from such manifest and irresistible proofs of a better administration, as will overcome all their antecedent propensities. … But even in that case, the State governments could have little to apprehend, because it is only within a certain sphere, that the federal power can, in the nature of things, be advantageously administered.

James Madison in Federalist No. 46

When rulers turn to war

… absolute monarchs will often make wars when their nations are to get nothing by it, but for purposes and objects merely personal, such as, a thirst for military glory, revenge for personal affronts; ambitions or private compacts to aggrandize or support their particular families, or partisans. These … often lead him to engage in wars not sanctioned by justice, or the voice and interests of his people.  

John Jay in Federalist No. 4