Well, indeed it seems almost impossible to get a good "rules of democracy", but if the majority wants something and they don't get it, that's the tyranny of the minority, that kind of defeats the purpose of democracy. (It's easy to say that passing new motions/resolutions/laws require consensus, but if the current system benefits a minority that can block the new laws ... you have a problem.)
Obviously, on the other hand if 50% + 1 can do whatever just happens to be on their mind, that seems like a very-very bad (or good, if you are the more evil-er sibling to Satan) recipe for disaster.
...
And here were are. Extreme polarization, fight for survival, everything is up for grabs (voting rights, citizenship/deportation, budget, supreme court seats, filibuster).
Justice is hard. (Rawls' Theory of Justice proposes that what's fair is just, and it defines that as a reflective equilibrium ... which seems a pretty elegant solution - especially if you have spent too much time in abstract math classes.)