Would a national language be unifying / disunifying?

[MineralMan]

12. And they do. But, we also have many recent immigrants

who are not comfortable using English. Many recent immigrants. In some places, there are very many of them. In my own city, St. Paul, MN, we have large populations of Hmong and Somali immigrants, for example. As is typical with immigrant communities, the elders and new immigrants still speak primarily their native language. The next generation speaks both English and the native language. The generation after that speaks English almost exclusively. It's a natural progression.

We welcome immigrants in the United States. That means helping, not hindering them. Part of that help is communicating important things to them in their own language, so those things can be completely understood. In the meantime, we aid them in learning English. It takes years for new immigrants to become citizens, and years for adults to become comfortable in a new language.

It's not really so hard to figure out, I think.

It's all part of being a nation that looks after its residents. Why would we change that?