Jay Cost of National Review Online explains the impact of diversity on national cohesion.
A mantra we hear everywhere these days is that diversity is a good thing. And no doubt, it is. Diversity facilitates an exchange of ideas and opinions, and it promotes economic growth. Moreover, the alternative to diversity is to suppress the views and opinions of some subset of citizens, which is completely unacceptable in a republic.
But diversity does create challenges for civil society, even if on balance it is beneficial to the nation. In particular, it facilitates the gridlock that has recently come to define our politics.
Now, to be sure, gridlock is a consequence of multiple causes — too many to enumerate in a column such as this. Still, a look back at the origin of the Constitution suggests how diversity can stymie public-policy initiatives under our system of government. …
… So what happens when the people in a nation are especially diverse? They may come together around shared goals, but it’s more likely that they will not agree on what those shared goals should be. Indeed, when it comes to deciding what’s truly in the national interest, it’s possible that the diverse groups will never agree on anything of substance.