I prefer "UrbAn Design" to Urban Planning, which I see as one particularly central-ConTrol oriented approach to Urban Design. Even Design is a word which conjures up a central intention which I think is inappropriate, but I'll let that slide for now.
Robert Moses destroyed big chunks of NYC through Urban Planning. Mass Public Housing for the poor, Neighborhood destruction via highway construction, over-ZonIng, etc. Hopefully he's in a Circle Of Hell.
Politically, cities are often affected by state-level and federal-level rules, mandates, etc. Is there potential for Urban Secession?