In Essay #51, what does Madison agree with Hamilton about in terms of social class?

In Federalist 51, Madison acknowledges that the "have nots" in any society are extremely likely to attack the "haves." Like Hamilton, Madison believed that class struggle was inseparable from politics. "It is of great importance in a republic not only to guard against the oppression of its rulers," Madison writes, "but to guard one part of the society against the injustice of the other. Different interests necessarily exist in different classes of citizens. If a majority be united by a common interest the rights of the minority will be insecure."