The truest true fact of American politics is that no candidate running this year is going to upset or even challenge the suburban sprawl industry. Sprawl is the endless increase in housing supply, the endless outward redistribution of population from cities and older suburbs, the endless federal subsidy for roads, and the endless chatter about "good schools" that is just a code for "schools without poor, visible minorities" that dominates American political life.

Americans tend to believe that sprawl is a natural consequence of "free market" forces when, in fact, sprawl is a consequence of governmental decision-making made by governments that are responsive to one single industry. Sprawl exists because of a bipartisan commitment to avoiding any talk about reining in the immense power of the real-estate industry.

That means that the long-avoided discussions America ought to have on race, on climate change, on imported energy, on highway construction and on agriculture will all continue to lack a certain element of reality.

Meanwhile, as the silence continues, sprawl continues to rule. And American cities will continue to die.

Folks in Northeast Ohio may be forgiven for believing that this is a local phenomenon, what with the steady stream of reports on Cleveland's and Cuyahoga County's population losses.

Did you know that it's Buffalo's problem, too? And Boston's? And San Francisco's?

In 2005, the Census Bureau measured domestic migration - people moving within the United States - from 1990 to 2000, and from 2000 to 2004. The report provides the number of people moving into and out of each state and the 25 largest metropolitan areas. Cities everywhere are in steep decline, while suburbs are "growing" - which means that population is being redistributed. Thanks to immense national, state and local subsidies, population is being shifted out of cities and older suburbs and into sprawling suburbs.

Cuyahoga County lost about 98,000 residents between 2000 and 2007, according to a recent Plain Dealer analysis of Census data - 13,000 last year alone - for a 7-percent decrease.

Cincinnati's population dropped over 9 percent in the last decade. After the next decennial Census in 2010, Ohio is expected to lose Congressional representation because Ohio - like all the states of the Northeast and Midwest - is experiencing sprawl without growth.

So far, Barack Obama is the only candidate who is speaking about Urban America. But he is speaking within the bounds of the 1960s paradigm about cities. His talk is all about the poverty of the deserted minorities of central cities, and not about the huge countervailing incentives that keep poor people marooned there. Obama is speaking - albeit courageously and intelligently - within the bounds of a paradigm that seems to work for politicians but which economists and a couple of insightful ex-mayors understand is obsolete.

A major 2007 initiative of the Brookings Institution's Center for Metropolitan Studies was to get thought-leaders across many disciplines to start thinking about cities again - not as enclaves but as the indispensable centers of metropolitan regional economies. Economies, not municipal boundaries, are the issue. Metro areas, the Brookings thinking suggests, have to be thought of the way we used to think of Athens and Rome - as city-states.

But still, the politicians' paradigm of cities as defined within old boundaries, rather than as regional economies that need to be managed, governed, planned, invested in and serviced regionally, persists.

Governmentally, cities remain isolated. Dying cities, in the words of former Albuquerque mayor David Rusk, are dying because they are trapped within "iron boxes."

Rusk's challenge to the paradigm isn't new. He and others spoke in the mid-1990s about how Cleveland, Cincinnati, Buffalo and most other cities in the Northeast and Midwest cannot annex their suburbs and have no planning power over their suburbs, and so remain isolated. That means that suburbs get to make their own planning and spending decisions as if they were independent, supreme, self-sustaining entities rather than components of regional economies.

Towns are the problem. Towns disrupt regional planning. Towns insist on going it alone. Towns poach development from cities and from each other. And towns demand that subsidies flow, in the form of direct government-to-government aid from the state and in road and highway maintenance from counties, the state and the feds. State and federal highway funds pour into suburban towns in amounts that dwarf the funds invested in cities.

So in a marketplace where there is already a huge oversupply of housing, the availability of county, state, and federal funds to build new roads and to maintain an already-overbuilt infrastructure leads to more and more subdivisions being built.

More sprawl.

And no presidential candidates are saying anything about it.

If our politics is going to be run by towns, is there any hope for cities or for metro regions?

Washington has been stuck in the 1960s mindset - which is, to be brutal about it, that cities are for the very rich and the very poor, and that suburbs are for white folks, and that there's nothing to be done about it because the "free market" means that folks are going to live where they're going to live, so we might as well just parse out money to suburbs for roads and to cities for anti-poverty programs.

Cities will continue to get special aid. Suburban real-estate developers will continue to receive their subsidies for further sprawl through the town governments they already control. Thus town officials in suburban Cleveland and suburban Cincinnati and suburbs throughout much of the country will continue to do what town officials do - which is to facilitate the sprawl that kills cities.

Because the inevitable alternative is something like this: If cities are to live, the power of town governments must die. That's a paradigm shift that would disrupt everything we think we "know" about race relations, transportation, imported oil, agriculture and democracy.

But wait-isn't that just the sort of change we've all said we need?