The workings of the Constitutional convention and the ratification debate can be argued both ways: Power Elite, because the delegate members were of the upper class, wanting a central government with real power, and Pluralist, because of the compromises made when amending the Articles of Confederation and also when working to ratify the Constitution. My perspective focuses on the pluralist theory, political decisions and compromises among groups.
The states involved in the convention were groups, or rather subunits of a nation, which interacted and discussed their interests in order to create the constitution. Within these groups delegates were chosen to represent each state, and ideologies were conflicting. There were delegates of whom the majority were strong nationalists with diverse political believes. Some with democratic principles wanting a central government founded on popular support, while other groups supported a central government with republican principles, and even more extreme were those who were monarchists. These groups created plans as well as controversies. Large states wanted more influence, small states felt threatened but compromises made by the groups allowed them to arrive at an agreement. The battle over ratification between Federalists, who wanted a strong central government, and the Anti-federalists, who feared that the strong central government could threaten the liberty of the people, showed a struggle in satisfying each other's interests. After long debates compromises and accommodations were made to reach an agreement. The proposal of a government scheme by Madison is an example of such compromises. He put forth that there could be three branches (executive, legislative, judicial) of government, independent of each other but cooperating to govern. No one group would have ultimate power but rather a system of checks and balances. .
The political decisions were made by the upper class or elite making a good argument for the power elite, however, the process by which they arrived at their decisions was pluralist in nature.