The theme of freedom and tyranny is pretty much always gonna come up when we're dealing with the founding of the United States. "Freedom Vs. Tyranny" was pretty much the buzzword of the Revolution—going through the revolutionary period without mentioning it would be like going through the 60's and forgetting to mention tie-dye shirts.
After the former-colonies were all once-bitten-twice-shy about another tyrannical governments (Thanks for that one, Britain), the Federalists had to address those concerns in writing the Federalists papers. In 10 and 51, one of Madison's goals is to convince the various state legislatures that a strong centralized government can actually help to preserve freedom and oppose tyranny, instead of the other way around.
One of the ways Madison deals with the question of a centralized government being too tyrannical is to rephrase the debate entirely. Instead of an overly-strong government being the source of tyranny in America, the unchecked power of majority factions in American politics is. By identifying faction power as the enemy of freedom, he's able to rhetorically place a strong centralized government on the side of freedom.
Madison's concept of freedom is not exactly how we would define freedom. He condemns anarchy, which is theoretically the most free form of government, because there is no government control at all. What Madison refers to as freedom more like the freedom to have your rights as a citizen respected, and that comes with a restriction on different groups' powers.
Faction politics are what the Federalist papers portray as the #1 danger…even riskier than crocodiles or living down the street from your favorite taco truck.
Democracy, if unchecked, turns the country into one big game of catch-the-votes, and vote-catching can be done a lot of different ways besides just having a good platform. A savvy politician can just pick a popular issue, and then ride it straight into power-land.
Not only that, but if one group is able to catch a majority of those votes, then there is nothing that can be done to protect the rights any of the groups whose vote-nets came up a bit emptier.
Madison's proposition for the structure of the legislative branch fits nicely in with the goal of keeping majority power in line. The House of Representatives gets proportional representation to state population, while the Senate gets equal representation.
Conversely, critics of the Federalist cause accuse them of setting up a system in which the minority in power gets to control the majority of citizens. At the heart of the debate is the question of the nature of the majority in a democracy—one group says the majority is the will of the people, while the other says that the majority is just a mob that shouldn't be given the keys to the kingdom—er, democracy.
Both Federalist papers are basically an explanation of the rulebook that is the U.S. Constitution—don't mess with the Constitution—and both are all about showing how you can preserve liberty through carefully structuring a government against negative factors.
While the spirit of Federalist Papers 10 and 51 is how to preserve civil liberties, the way in which it does so is by a heavy heaping of government oversight.
They were Federalists after all, and were big supporters of a hands-on central government. Rules and order, according to the Federalists, are what allows for true freedoms. It kind of takes a while to wrap your head around the reasoning, but Madison's all about explaining that factoid.
Both Federalist 10 and 51 assert that without the tempering structure of a strong central government, faction struggle would definitely destabilize society.
The Anti-Federalists' and Federalists' opposing opinions on the need for a strong central government has a lot to do with their views on what the Revolution was for.