The idea of suburbia is so deep-seated it’s become almost a foundational myth: The suburbs are prosperous, tidy, homogenous, and boring. Upwardly mobile families move there to escape urban disorder, crime, and congestion, leaving the inner cities to spin in a downward cycle of disinvestment. In particular, the suburbs are where white people fled in reaction to the Great Migration of Southern blacks to the cities of the North and West in the early and mid-20th century.

It’s an idea that began taking root more than a century ago, when improved transportation made it possible to commute from what had been hardscrabble boondocks; “streetcar suburbs” became beachheads of metropolitan expansion. The post-World-War-II auto suburbs followed, reinforcing the status of suburbia as middle-class enclave; to live there you had to be able to afford a car. The idea of suburbia was so strong it expanded beyond suburban borders: As late as 1991 Joel Garreau could write, in his influential Edge City: Life on the New Frontier, that some in-city neighborhoods were so “beautiful, affluent, quiet,” with their “trees, lawns, and single-family detached homes” they could be called suburban. “For all practical purposes, they look and function like suburbs.”

Maybe. But more and more, across the country and in the suburban rings around Seattle, many actual suburbs do not look and function that way. In once-redlined urban neighborhoods like the Central Area and Columbia City, white flight has long since reversed itself and gentrification has succeeded decay as a prevailing neighborhood anxiety. High housing prices have pushed the poor and near-poor out further, into outlying neighborhoods and suburban towns. Where “suburbanization” summed up America’s social changes in the 1950s, “suburbanization of poverty” has become the new buzzword — nudged along by surprising findings in the 2010 U.S. Census and a much-discussed study from the Brookings Institution.

That term suggests a bleak devolution: Just as hard times are putting the squeeze on everybody, those who most need access to transit, jobs, and public services are getting pushed out to new suburban ghettoes where, as Brookings co-authors Elizabeth Kneebone and Alan Berube note, "the safety net is patchy and stretched thin to begin with.” If so, then the holes should be gaping in Southeast King County, the local epicenter of this new suburbanization.

But a closer look at the situation in Kent, the largest city in the south county, and at the ways both public officials and church and nonprofit service providers are responding to changing economics and demographics, tells another story as well — one not just of need and hardship (which are indeed severe) but of ingenuity, inclusiveness, and community coalescence. Furthermore, the growth in poverty in Kent and neighboring cities in South King County reflects not just push-out but pull-in: South King County and its counterparts in the suburban rings of other American cities have become magnets for a different sort of Great Immigration that may ultimately enrich them.

The changes in the suburban population are certainly dramatic. Between 2000 and 2010, according to census data crunched by the Brookings researchers, the number of poor people living in the suburbs of major cities grew 53 percent, while the number in the cities themselves rose just 23 percent. By 2010, the suburbs were home to a third of all Americans living under the official poverty level — more than the numbers living in cities, smaller towns, and rural areas. The changes have proceeded even faster in Pugetopolis than elsewhere in the country; 68 percent of the poor in the three counties surrounding Seattle now live in the suburbs. And they’ve proceeded fastest of all in South King County.

As the Brookings maps show, the poverty rate rose in 27 South King County census tracts between 2000 and 2010; of the 21 tracts in all of King, Snohomish, and Pierce counties where it rose more than 10 percent, 13 are in the south county. The poverty rate fell, more modestly, in just 11 tracts there. By contrast, it fell in 25 Seattle census tracts during the same period, and rose in just 11.

The results: Four South King County cities — Burien followed by Kent, Tukwila, and SeaTac — have the largest shares of residents receiving Medicaid (35 percent in Kent’s case) in Pugetopolis. Proportionately more of their residents, together with Tacoma’s, receive food stamps than any other city’s. Half the kids in Kent and more than half in neighboring Auburn and Renton receive free or reduced-price school lunches. Kent’s per capita income, $26,470, is just 70 percent of the statewide average. Its official poverty rate, 14.5 percent, is half again as high as King County’s and, reflecting an average over the five years from 2005 through 2009, doubtless lags behind today’s distressed reality.

The effects show in Kent’s storefronts. Some in the sprawling, economically and ethnically mixed East Hill section of town are boarded up. Below the hill, the City of Kent has worked hard to spruce up and invigorate its downtown, with the Sounder commuter rail station as magnet and centerpiece.

Next to the station, the Kent Station “lifestyle center” (shopping plus a community college satellite campus) entices commuters and car-bound shoppers. The storefronts in the adjacent original downtown, marked by “Historic District” signs, are mostly spruced up, and planters and benches decorate the sidewalks. But at 5:10 p.m. on a cold but dry Thursday, the sidewalks were empty and many of the shops closed. The most brightly lit establishment was the Children’s Hospital Thrift Store; the busiest, the dismal Pied Piper Pub. Three scruffy-looking guys carried on an animated conversation at one corner; the homeless have become a fixture in Kent, as have their camps in the sprawling parks outside town and along the Green River.

The Kent Station center is much livelier, but even here a chill has set in. Tami Sleeman used to operate a hobby shop in the mall with her husband. But after the recession hit their business withered, and they shut down. She says five of the six local, non-chain stores in the mall did also. “We were the only ones who didn’t file bankruptcy.”

Oldtimers still recall a Kent Valley that was nearly all white, native-born, and jealously parochial. But that recollection will soon be as faded as the hop fields that once grew in the rich volcanic/alluvial soil, and which gave the valley its name (after Kent, England, home of the classic Kent golden hops). For more than a century, overseas immigrants, from Chinese traders and laborers in the 1870s and ’80s to Vietnamese boat people and the survivors of Cambodia’s killing fields and Ethiopia’s famines in the 1970s and ’80s, tended to settle in Seattle, along a swath that spread from the International District down Beacon Hill and the Rainier Valley.

That changed with the arrival of thousands of religious refugees from the disintegrating Soviet Union, who clustered in the south county, especially Kent. Even now at the Valley Harvest supermarket on SE 104th Street you’ll find a smattering of Californian, Bulgarian, and Moldovan wines, more Romanians (though Vampire Vineyards’ “Dracula Red” is actually from California), and a wide selection of Georgian vintages.

You’ll also find nopales, lemongrass, chayote, and nearly any other exotic produce or baked good you can imagine. Galletas de nuez share a case with bánh mì. I stood at the register behind a tall turbaned Sikh, a woman wearing bright beaded West African market-day regalia, and an Eastern European gent tapping his feet to the mariachi music on the loudspeaker. The rundown strip mall across the street is home to Punjab Sweets, Pacific Market Halal Meats, and, squaring off against the Henna Beauty Salon, the Khoobsurat Boutique and Beauty Parlor. Plus the usual pizza parlor, smoke shop, sports bar, and Pawn Xchange.