Nearly all major cities are controlled by Democrats most of the time. Since the GOP offers few policy ideas that address urban issues, urban voters seldom choose Republican leaders. And that's similar around the world: most major cities have center-left leadership most of the time. What sets the shitholes apart from the high-functioning liberal cities (e.g., Boston, Seattle, San Francisco, NYC, London, Berlin, Paris, etc.) is generally not the government of the city proper, but rather the support it gets from surrounding areas. In liberal regions where the surrounding areas see the city as an economic and cultural engine to be nurtured, cities thrive. In conservative regions where the surrounding areas see the city as a place of dangerous minorities, to be kept under heel with draconian policing, even as its starved of other funds, cities tend to be in rough shape.