Final answer:
James Madison believed that a large, diverse republic would be best for the common good.
Step-by-step explanation:
The delegate who believed that a large, diverse republic would be best for the common good was James Madison. As one of the Founding Fathers and a key architect of the United States Constitution, Madison argued in favor of a strong central government that could effectively represent and protect the interests of a wide range of citizens. In support of his position, he wrote several essays in The Federalist Papers, alongside Alexander Hamilton and John Jay, outlining the benefits of a large republic with diverse interests and perspectives.