In the fast-changing political battleground that is suburban Denver, Somali families dine on goat soup and fish fritters in a onetime Chinese restaurant where golden dragons still guard the doorways. Where the English Teacup cafe once stood, a new Japanese dessert bar now stays open late, selling green tea soft-serve and fish-shaped pastries to lines of Korean and Latino teenagers. And up and down Havana Street, auto lots once run by the likes of Dealin’ Doug are now Ethio-Motors, Maaliki Motors and Jordan Motors — names that reflect the new owners and new customers who are part of a hyperspeed...