All excerpts taken from the edition available at the National Archives. 
Before the U.S. had a Constitution, but after winning its independence from Great Britain, there were eight years during which the thirteen colonies that comprised it were organized under the Articles of Confederation. This was a boon to states’ rights, as the Articles entailed a small central government. The framers of what would become the Constitution felt that this system was inadequate, and set out to replace it. But they could not do so without making the case to their fellow citizens that it should indeed be replaced. The Federalist Papers were a series of essays written by three men — James Madison, Alexander Hamilton, and John Jay — under the pseudonym Publius. Their aim was to demonstrate the benefits of a stronger federal government and allay the fears of those who suspected it would spell the end of the colonists’ liberty.
Madison wrote Federalist #10 in 1787, the same year that the U.S. Constitution was completed (although it would take two more years for it to be ratified and enter into effect). Published in the New York Packet, it is addressed to the people of New York, whose Governor was reluctant to join the new union, and where the idea of secession was being floated as an alternative. His arguments can tell us a great deal about the priorities and concerns that motivated both the framers of the Constitution and their audience.
Madison begins by recommending the new Constitution as the solution to a problem he calls “faction”: “Among the numerous advantages promised by a well-constructed Union, none deserves to be more accurately developed than its tendency to break and control the violence of faction.” At first glance, “faction” seems like a synonym of politics, or ideological disagreement. But what Madison finds troubling isn’t mere disagreement so much as it is political violence and the instability that comes with it. Madison then posits a disjunction between two possible strategies for handling this problem: addressing the causes or the effects of such faction.
He considers two possible ways to address the causes. The first is “destroying the liberty which is essential to its [faction’s] existence”. What exactly he means by liberty here is open to interpretation. If he’s saying that faction might be undone by passing laws against its verbal and political expression, then he’s arguing in favor of free speech and freedom of assembly. But this comes a little late in the game to count as an attack on the causes of faction — he might instead be using “liberty” as a shorthand for absolute property rights (as liberals are wont to do), the right to get rich. “Destroying liberty” would refer, then, to removing the economic differences that cause fault lines in opinion to emerge. Crucially, Madison presupposes private property, which gives rise to zero-sum conflicts between competing interests by its nature. If my flourishing is reliant on a pot that belongs only to me, then my only interest is in making that pot bigger, and other people, seeing me through the eyes of their own pots, can only perceive that as what it is — a threat. Public property would carry with it free-rider problems but also generate a substantial common interest (not least against free-riding).
The second way Madison can imagine addressing the causes of faction is by “giving to every citizen the same opinions, the same passions, and the same interests.” He finds this option no more viable or attractive than the first. It’s hard to miss the Orwellian resonances of Madison’s fears about totalitarianism, which is both evil and totally “impracticable”. In considering this possibility, Madison makes the good materialist point that “As long as the connection subsists between [a man’s] reason and his self-love, his opinions and his passions will have a reciprocal influence on each other; and the former will be objects to which the latter will attach themselves.” His next move, though, is the very un-materialist one of deducing property rights immediately from “diversity in the faculties of men”. People are different; therefore it would be folly to make despotic inroads on the rights of property. Due to his adamantine commitment to private property as flowing directly from “different and unequal faculties”, he is once again unable to imagine a radical solution to the problem of faction. No just solution to the causes of faction is possible, since “The latent causes of faction are thus sown in the nature of man”.
Having rejected the strategy of removing the causes of faction, he turns his attention to the strategy of mitigating its effects, which he finds much more promising. It becomes abundantly clear that the principal danger he perceives is that of majority faction, that is, the shared interest of the poor in downward redistribution. Other factions are a relatively trivial problem, since, as he puts it, “If a faction consists of less than a majority, relief is supplied by the republican principle, which enables the majority to defeat its sinister views by regular vote. It may clog the administration, it may convulse the society; but it will be unable to execute and mask its violence under the forms of the Constitution”. What he considers “improper and wicked” and harder to defend against are projects like the “rage for paper money, for an abolition of debts, for an equal division of property”. But the new Constitution, he believes, will stand as a bulwark against such projects.
Madison is not worried by faction as such as much as he is worried by the spectre of communism, which he calls democracy, or majority faction (what Tocqueville would later dub the Tyranny of the Majority). On this basis he argues for a large republic as opposed to a smaller one, an argument that works out to the advantage of a stronger central government as opposed to a weaker one. He claims that every republic, regardless of its size, cannot have a representative body that is too big (things would get messy) or too small (people would be underrepresented). Therefore, all republics having optimized for parliaments of approximately the same size, the chances of filling one’s parliament with “fit characters” go up with a larger pool of citizens to choose from (also assuming that “fit characters” are just as common in small republics as large ones).
It should hardly be necessary to clarify that “fit characters” is a euphemism for rich white guys. One of the principal benefits of a republic as opposed to a democracy is that the representatives can be a non-representative sample of the population. It is not assumed that they will be free of faction, since faction, remember, derives immediately from human nature. Instead, they can be trusted to be a brake on majority faction. Private individuals pursuing their private interests can’t threaten the stability of the republic as long as there’s enough of them, and there’s a little bit of disagreement among them. Madison expresses disapproval of “the vicious arts by which elections are too often carried”, but claims that these become more difficult with a larger body of electors. The same principle, in fact, works against majority faction: “where there is a consciousness of unjust or dishonorable purposes [i.e. affronts to property], communication is always checked by distrust in proportion to the number whose concurrence is necessary”.
A large republic, in other words, creates a tremendous coordination problem for the poor majority. Insofar as the Constitution guarantees that these conflicts are kept outside the political system, which should occupy itself only with hashing out economic differences within the ranks of the bourgeoisie, it preserves the stability of the United States. At no point does it seem to occur to Madison that designing a system expressly meant to give a political monopoly to a unrepresentative ruling class could backfire.
There are two ways to proceed from here: pointing out what is stupid, undesirable and unrealistic about Madison’s lawful-evil utopia, and acknowledging his farsightedness in designing a system that has in fact proven quite resistant to revolution. On the one hand, once majority faction is ruled out and minority faction is ruled in, it won’t take long for the apparent disagreements between bourgeois interests to coalesce into something like a homogenous class dictatorship, which can then practice “the vicious arts” of election-rigging unopposed. One cannot trust in petty rivalry between members of the bourgeoisie to safeguard the public interest, for the same reason that you can’t leave a chicken alone with two foxes on one side of the river. Insofar as this abandonment of the general welfare is destabilizing, you have designed an unstable system, one prone to hyperexploitation, inequality, imperialism, and environmental despoliation. Minority faction is indifferent to the species’ shared interest in survival in a way that majority faction cannot be; guarding against the latter necessarily empowers the former, in all its cruelty and selfishness. Equating affronts to property with “violence” has made for one of the most violent societies in history. The bill eventually comes due.
But it must be admitted that the basic plan of keeping government occupied with intra-bourgeois struggles has pretty much worked out for the U.S. ruling class. A large republic has made it very difficult to coordinate large-scale efforts at rebellion — so far, the most significant one, the secession of a Confederacy of slave states, has come from the right. The brisk pace of capitalist accumulation has faced hardly any serious challenges. The system of checks and balances, along with self-consciously antidemocratic institutions like the Senate, the Supreme Court, and the Electoral College (not to mention the more recent two-party duopoly), have made political power in the U.S. nearly unassailable, and fundamental change nearly unthinkable. This despite the manifest inability of such a system to meaningfully address the greatest dangers threatening humanity today: global warming and nuclear war. The USA was a missile fired into the future in 1787 to destroy the planet. Whether it succeeds depends on how we handle those vicious remnants of a bygone age.