From Jonah Goldberg at National Review, Who Cares about National Unity?:

The founders wanted to create a new kind of country where individuals — and individual communities — could pursue happiness as they saw fit. They didn’t achieve that instantaneously, and we still don’t have it in meaningful respects, but they set up the machinery to make it achievable. This doesn’t mean the founders were against unity in all circumstances. Their attitude could be described as in necessariis unitas, in non-necessariis libertas, in utrisque caritas. In essential things unity, in non-essential things liberty, and in all things charity. In other words, they understood that unity was a powerful tool, best used sparingly and only when truly needed. Odds are good that this was — or is — the basic, unstated rule in your own family. Good parents don’t demand total unity from their children, dictating what hobbies and interests they can have. We might force our kids to finish their broccoli, but even then we don’t demand they “celebrate broccoli!” I wish my daughter shared my interest in certain things, but I have no interest in forcing her too, in part because I know that’s futile. Spouses reserve unity as an imperative for the truly important things. My wife hates my cigars and has a? fondness for “wizard shows.” But we tend to agree on the big things. That seems right to me.

What is fascinating to me is that in the centuries since the Enlightenment, unbridled unity, enforced and encouraged from above, has been the single greatest source of evil, misery, and oppression on a mass scale, and yet we still treat unity like some unalloyed good.

..unity is the mask power wears to justify itself. What liberals are nostalgic for is not unity but the kind of power they had back in the good old days. They can’t say, “Man, I really miss having the kind of power to do what we wanted,” so they gauze it up with false phantasms of national unity lost.