Ah the popular "the US is too large and too diverse to function" excuse. Not that long ago the size and diversity was seen as a unique strength of the US. When did "Give me your tired, your poor, your huddled masses yearning to breathe free, the wretched refuse of your teeming shore. Send these, the homeless, tempest-tossed to me, I lift my lamp beside the golden door!" become "societies only work when they are homogeneous"?
He didn't say that the US doesn't "work". Note that he put "freedoms" in quotes in reference to the parent comment that twisted the definition of freedom to include socialist programs. It's true those won't work in the US but as the original poster commented: