St. George Tucker was not the constitutional expert that Madison and Hamilton were and his opinion is worthless up against theirs. And the constitution was a creation of the whole American People not of states. States were DIRECTED by Congress to create conventions of the People gathered in states to consider ratification. This was for administrative convenience and to avoid the political expression of the states, the legislatures.
Madison opposed secession, but he also conceded it was an option of last resort to escape from intolerable oppression (though he said such an act, while perhaps justified, would constitute revolution).