As we wrote in this space yesterday, it was "American Dream Week" at the White House last week. This can sound like an airy concept, but it was at the heart of Donald Trump's victory in the presidential election.

"The American Dream is dead," he proclaimed in his Trump Tower announcement in June 2015, eliciting the yell of one supporter, "Bring it Back!" That was the implicit promise in "Make America Great Again."

Any conservative, however, knows that the president cannot either by himself on in the space of his presidency restore the American Dream. It can be restored only slowly, at the local and family level.

That's because it is rooted in intact families and strong communities. This opinion isn't an esoteric one confined to conservatives but is the incontrovertible conclusion of empirical data and social science.

One good definition of the American Dream is the hope that your children can do better than you did. Economic mobility is unevenly distributed around the country. In some places, there's plenty of it, but in others, you're almost guaranteed to end up where you started, both literally and figuratively.