Why are Republicans scared of America’s cities?

Why are senior Republicans describing cities as “war-zones”, security threats and spaces of total disorder? In May, the New York Times’ Robert Draper asked Donald Trump to name the most dangerous place he has visited in the world. After initially joking “Brooklyn”, the Republican presidential nominee answered “No… there are places in America that are among the most dangerous in the world. You go to places like Oakland. Or Ferguson. The crime numbers are worse. Seriously.” Two months later, Trump underlined the point, telling a crowd in Ohio that “you could go to war zones in countries that we’re fighting and it’s safer than living in some of our inner cities that are run by the Democrats.” This picture of urban degeneration featured heavily in his speech at the Republican National Convention, in which he promised that “safety will be restored”: