No matter how the upcoming election turns out, chances are the analysts won’t have missed one prediction: In many metro areas across the country, the geography of voting will continue to change, with more closer-in suburbs joining the core cities in voting Democratic.

Newer suburbs and farther out exurbs, where much of the population has been moving, have heavily supported the GOP in the past dozen years. This election will test that political dynamic, but the underlying demographic movements will remain unchanged.

The patterns of voting are only one indicator of how metropolitan America is changing. The revival of most of our large and midsize cities has spread from the two coasts inland — to St. Louis, Houston, Dallas, Denver, Memphis and on. Older suburbs, those generally developed in the quarter-century after World War II, find themselves increasingly challenged by blight and difficult demographics as their populations age; poorer residents are pressured out of the cities; and immigrants, many illegal, squeeze in, looking for lower-end jobs and cheaper rents.

The inner-suburban rings around cities still contain more people than the exurbs or cities, and most continue to grow. But the exurbs are exploding, in part because that’s where the jobs are moving, causing state and local officials charged with managing growth, building infrastructure, preserving open space, taming traffic, and curbing air and water pollution major headaches.

A demographic and economic snapshot of today’s metropolitan America yields a complicated picture. Some cities, such as Atlanta, are gaining population for the first time in decades. The Center City of Philadelphia has grown 11 percent in the past five years. But even those still losing people are enjoying an increase in per capita income because new residents moving in are wealthier than those leaving.

As suburbs become more diverse — one in six residents was a member of an ethnic minority in 1980, but now it’s one in three — many central cities are becoming less so. In San Francisco, the overall population has declined 5 percent in the past five years, but the black population is down by 20 percent and the Hispanic by 10 percent. The black populations of suburban Detroit counties such as Macomb have been soaring even as the city’s population continues its decline.

Gentrification of downtowns has accelerated in interior cities such as Milwaukee, Nashville and Albuquerque, much as it had grown in coastal cities during the past three decades. In Houston, it is occurring at a pace that only Texans could envision, so fast and on such a scale as to have become a political issue. Taking advantage of large swaths of vacant land, developers are building whole neighborhoods on a scale usually seen only in outer suburbs.

One of the most prominent emerging planning issues now is the increased density caused by infill development, especially skyward. Environmentalists and urbanists who reflexively used to oppose high-rise development are now trying to persuade existing residents of older communities to accept much taller and denser mixed-use developments as a way to promote less outward sprawl, shorter commutes and increased economic activity. Many older residents aren’t buying it, though. They refer to it as “vertical sprawl” and suspect that the real motive is to replace middle-class working neighborhoods with denser, high-design, hip multiuse development.

BACK IN TOWN

Some higher density projects are sidetracked, but the trend is clear. In St. Louis, Philadelphia, Minneapolis-St. Paul and New York, office space development is being crowded out by residential development. In lower Manhattan, which lost millions of square feet of office and commercial space when the World Trade Center fell, 8 million square feet of residential space has been added in the past five years. Nothing has yet been built to replace the WTC, even though corporate headquarters are beginning to return to the city.

Urbanists fret that while downtowns may be gaining people, they are losing jobs because downtown office space is shrinking as a share of total supply. A number of metro areas now are seeing reverse commutes, with city residents traveling to the suburbs not only to work in office parks, but increasingly to dine and be entertained also — while suburbanites travel into the city to do the same.

It’s a situation that is highly fluid, complex and subtle. If cities cannot continue to control crime and improve their schools, the impressive revival of urban centers may fizzle. If older suburbs cannot successfully rejuvenate themselves, they may prove to be the venue for the next metropolitan crisis. And if gasoline eventually sells for $5 a gallon, as some economists are predicting, or if governments simply no longer want to underwrite the added costs of continued sprawl, the exurban boom may bust.

Though free-market forces are powerful, state and local governments can make a difference in shaping future growth trends. And those governments in the future are going to have to integrate their planning and transportation systems more on a regional basis than they have been willing so far.

Peter Harkness is the editor and publisher of Governing magazine, published by Congressional Quarterly Inc.