For all the talk of American cities undergoing a renaissance, economic success has been concentrated in a few standout metropolises while the rest either struggle to keep up or fall further behind.

Why it matters: This winner-take-all dynamic has led to stark inequalities and rising tensions — both inside and outside city limits — that are helping to drive our politics off the rails.

The new and best-paying jobs are clustered in cities like San Francisco, New York and Seattle.

A widening chasm separates them and struggling post-industrial ones like Cleveland, Detroit and Newark.

And distressed areas are fading as their populations age and young workers head to coastal cities.