Can diversity be ‘too much of a good thing’? More Americans wonder.

Is there such a thing as too much diversity? While the idea that “our strength is in our diversity” has gained favor, some on the left wonder: “Shouldn’t there be core American values that unify?”

Jonette and Ken Christian have become a bit uneasy with the emphasis people place on the idea of diversity.

It’s a fraught subject to criticize, they say. As liberal Democrats living in Holden, Maine, they’ve sometimes been frustrated that even raising concerns about the scope of immigration policy, say, is often met with charges of...