On May 29, Edmund Randolph introduced the Virginia Plan containing 15 Resolutions.
Echoing, Madison's Vices of April 1787, he itemized five reasons why the Articles of Confederation must be radically altered.
The single most important reason why the delegates were gathered was because of what Madison referred to as the multiplicity, mutability, and injustice of legislation at the state level. To correct these deficiencies, the Virginia Plan removed the state legislatures both structurally, and in terms of powers, from any place in the new continental arrangement. Most importantly,
The "oracle" Montesquieu had argued that for a people to remain free, they must reside in small, homogeneous communities. Public virtue was needed to secure a republic and this sentiment was endangered in large, heterogeneous communities. It is the unique contribution of Madison to challenge this traditional theory of self-government head on. In fact, he stands it on its head! His first verbal articulation of this position occurs on June 6 where he argues that majority faction is the mortal disease of popular government and traditional solutions to factious politics will no longer work. He thus directly challenges the traditional claim that people are happier in small republics. Just the opposite; unless we spread people out over an extended orbit and filter their opinions, passions, and interests through a scheme of representation, then popular government will come to a violent end. This speech is the precursor to the famous Federalist 10 essay and is part of the political theory underlying the Virginia Plan.
There is a division of opinion in the scholarly literature concerning the motivation behind the introduction of the Virginia Plan. Some scholars credit Madison for his strategic brilliance in shifting the attention away from revising the Articles of Confederation to this new and bold plan. Other interpreters point out that it was introduced by Virginia, the largest state, that would benefit in terms of representation at the expense of the smaller states who received equal representation under the Articles of Confederation. A number of political theorists portray the Virginia Plan as making the novel case for "the large republic" theory over against the traditional "small republic" theory articulated by Roger Sherman on June 6. What is clear from both Randolph's arguments on May 29 and Madison's position on June 6 is that the Virginians saw state legislatures, in both large and small states, as dangerous to liberty and justice. What is also clear is that Madison sees no principled reason for the equal representation of states qua states.