James Madison, one of the most vocal members of America's Constitutional Convention, was constantly worried about the danger of what he called faction in a representative government. He worried that citizens might think of themselves as members of small groups, and might form deep allegiances to those groups, deep enough that the interests of the group outweighed concerns for the common good.

In some sense, that was natural and to be expected; Madison assumed that a man will of course look out for his family before all things. The same would probably be true about a man with respect to his close friends.  A faction, though, is (perhaps) a slightly different thing. A faction tends to have organization, often a formal organization. A faction is large enough to exert quite a bit of political leverage.  A union, for example, may be a faction (did anyone see The Irishman last year?). A political party may be a faction.

For Assignment:  Take a position concerning the role of factions in public life. Try to make it a narrow position, something like, "factions may present X problem", or "factions can benefit the city/state/nation/community/neighborhood in THIS way".  

You don't want to try to argue "factions are good" or "factions are bad", because the idea is too complex. Unless you focus your argument, you will end up saying very little.

Try instead to think of some aspect of the issue that might be interesting, and consider only that aspect.