In addition to Susan’s excellent analysis of the events of July 16 and 17—the hinge of the Convention, she accurately writes, defined as the days were by the Great Compromise—another issue repays careful attention.

That issue, which was debated on the 17th, was Madison’s lead balloon, or, perhaps better put, his white whale: the national veto on state laws. The motion on the floor was to empower the national government to strike down state laws that contravened the Constitution. Even this much was not enough for Madison, who had written to Washington before the Convention—with emphasis in the original—that the negative had to apply “in all cases whatsoever.” Otherwise the states would wriggle out of it with technicalities.

The veto has been generally regarded as evidence of Madison’s concern about majority abuses, like the abrogation of debts or the issuance of paper money, within the states. But this was not his foremost concern, as his remarks on July 17 indicate. What most concerned Madison was “the propensity of the States to pursue their particular interests in opposition to the general interest.” Madison sought the veto to ensure national majorities could prevail on national issues, or, conversely, that minorities of the whole (individual states) could not obstruct a majority of the whole.

The veto was likely doomed by Madison’s apparent concession on July 17 that it would have to involve some mechanism by which the states would need to submit laws to the national government for approval. Only three states voted in favor of the motion. What would become the Supremacy Clause was substituted for it. Madison was so concerned about the failure that he returned to the national negative as late as September 12. After the Convention, he wrote Jefferson that the lack of an effective means of controlling state incursions on the national government represented an existential defect in the Constitution.

The veto almost certainly never had much of a chance. It nonetheless provides important insights into Madison’s democratic thought.