Joel Kotkin

is a Presidential Fellow at Chapman University and author of "The City: A Global History"

Poor Pennsylvania. As the national media focus on the Keystone State, it has earned a new and less than admirable moniker: "the other Ohio."

Of course, this description also mirrors the hope of Hillary Rodham Clinton, for whom the hard-pressed, semidepressed Buckeye State presented a political field of dreams. Moreover, to be sure, Pennsylvania's Appalachian string of devastated former mining and mill towns constitutes its own private Ohio. The two states are similar in other ways; for example, proportions of African American and other minority residents - about 15 percent - also are roughly similar (Figure 1).

Beneath the similarities, however, are important and perhaps critical differences. Sen. Clinton's new message of old-style pessimism not surprisingly played well in Ohio, in large part because it has stronger ties to an old-line Great Lakes auto industry now in free fall. Outside of Columbus, its economy is generally so bad that, even though its housing prices did not rise much in the bubble, the state is still reeling with a rash of foreclosures.

In contrast, Pennsylvania's 3 percent job growth since 2003 - admittedly below the national average - has been jackrabbit-fast compared with Ohio's pathetic 0.5 percent. Most important, nowhere in the state remotely corresponds to the size, scale and complexity of the Philadelphia region, with its large concentrations of high-end technology and business-service employment.

"I'm insulted when people compare Pennsylvania to Ohio," says Brookings Institution demographer William Frey, himself a native of Allentown. "It's not a Rust Belt state, but a lot of it is like New Jersey."

Some may argue a place can receive bigger compliments, but an analysis by the Praxis Strategy Group certainly points out significant divergences between the Pennsylvania and Ohio. Although Pennsylvania also creaks a bit as an oldster state, it is clearly not losing people at anything like Ohio's rate. In fact, in this decade, Pennsylvania is gaining about as many migrants as it is losing.

Perhaps most important, Pennsylvania also fares much better in terms of holding on to people between the ages of 28 and 50 with college educations. It is nothing like the magnet for young brains that North Carolina (the site of the next major primary) is, but it is now losing only marginally in the race for younger, educated people. This is actually good by the standards of most Northeastern states.

This demographic group may prove a pivotal one for Sen. Obama: Along with African Americans, younger, educated people constitute his most reliable constituency. Their ranks made all the difference in Wisconsin, much to the surprise of a media that saw the Badger State as just another Midwestern basket case. Obama will need these younger, educated workers in Pennsylvania if he is to have any hope of offsetting Clinton's advantage with both older and working-class voters, as well as with the state's small but growing Latino population.

Perspective on the economy may be the best way to differentiate between the two candidates' constituencies, particularly with the current downturn. Younger, educated voters may not sense a Reaganesque "morning in America," but they appear comfortable enough to buy Obama's vague, but uplifting, message of "change." In contrast, Clinton's more hard-pressed working-class white voters need help right now and want to hear specific policies that seem to address their needs.

On a regional level, Obama's biggest hope rests where younger, educated voters are concentrated (Figure 2). Allegheny County, with its plethora of universities and medical facilities, is still one of the places in the state with an above-average share of educated younger residents, even though it has been losing more of them in recent years than gaining.

By far the greatest opportunity, however, is in the Philadelphia suburbs, where the proportion of people under 45 with at least a bachelor's degree stands at 50 percent above the national average. It is one place in the state with strong gains in this demographic group. One reason: Almost all the Philadelphia region's net jobs in finance, business services, and other high-wage professions are concentrated in these areas.

These "collar counties" could help turn greater Philadelphia into a potential bonanza for Obama. He is already well-positioned in the city, which boasts large pockets of proven Obama constituencies such as African Americans and young, largely childless white professionals.

The fast-growing Southeast and Northeast metros, places such as York and Lancaster to the south and Allentown in the north, also might offer some gains for Obama. These areas, our data suggest, also have begun attracting educated workers, many of whom commute across the state line to work in metro Washington or New Jersey. A substantial number also endure the morning death march to Manhattan.

"Housing prices in eastern Pennsylvania are making it very attractive to people who work in and around New York," reports Brookings' Frey. "Allentown may be the fastest-growing large metro in the Northeast."

Yet even if these demographic trends may help Obama, the Clinton campaign probably still holds the stronger hand across the state. Most of central and Western Pennsylvania - with exceptions around Harrisburg and State College - remain overwhelmingly white, relatively low in education levels, and economically distressed. Like much of Ohio, these areas seem primed to go heavily for Clinton.

Ultimately, the election in Pennsylvania will turn on two things. One will be the relative ability of each campaign to mobilize their constituencies. Obama needs to inspire his millennial-generation enthusiasts and bring them to the polls. Clinton must energize the well-honed Democratic machines across the state. Money is likely not to be as decisive as organization and demographics. Obama spent twice as much on media as Clinton in Ohio but still lost decisively.

The second critical factor may be the extent to which each campaign can poach on the other's turf. Clinton, for example, could hope that Mayor Nutter's support for her can cut into Obama's African American base. Obama might be able to repeat his success in Wisconsin and elsewhere with white, male, working-class voters who have shown less enthusiasm than their female counterparts have for Clinton.

As has been commonly asserted, the demographics and economic realities of Pennsylvania still favor the Clinton campaign, but not as decisively as in far more dismal Ohio.

To blunt Clinton's big-state momentum, Obama will have to run a more effective campaign focused on his key constituencies. If he can do this, he may be able to regain the upper hand in the next big contest on May 6 in North Carolina, a state whose more youthful demographics, large black population, and much stronger economy work to his advantage.