The practical task is therefore to control faction's effects. A minority faction can usually be defeated through ordinary voting because it lacks the votes to rule. A majority faction is more dangerous. If most citizens share an unjust purpose, they can use the lawful machinery of government against a minority. Madison did not solve this problem by requiring unanimity or by banning political organization. He relied on a representative republic, in which elected officials deliberate and act for the public, combined with a large territory containing many different interests.

Size is part of the mechanism, not a guarantee of virtue. In a large, diverse republic, an unjust majority is less likely to share exactly the same interest across the whole country. Even if a harmful passion arises locally, coordinating it across many communities becomes more difficult. Representation may also refine public views by placing decisions in the hands of elected officials. Madison admitted that representatives can betray the public interest, so the argument is probabilistic: the design reduces the opportunity for durable majority oppression; it does not eliminate selfish groups, bad leaders, or political conflict.

The most important distinction is between No. 10 and No. 51. No. 10 works mainly through the social and electoral environment outside government: representation, territorial scale, and a multiplicity of interests. No. 51 works through the internal design of government: branches with constitutional tools and incentives to resist one another. A scenario in which several groups prevent any single coalition from dominating points toward No. 10. A scenario in which Congress checks a president or the Senate checks an appointment points toward No. 51. Modern pluralism resembles Madison's competition among interests, but Federalist No. 10 is specifically a constitutional defense of the extended representative republic.

Video lesson: The Constitution, the Articles, and Federalism: Crash Course US History #8