Philadelphia is a city in a state of churn. Newcomers in their 20s and 30s are filling up rowhouses by the hundreds, transforming whole neighborhoods overnight. Thanks to an influx of immigrants, more languages than ever pepper our streets. Hardly a week goes by without the opening of a new chef-driven restaurant, but good luck getting a last-minute reservation on Saturday evening.

When it comes to Philadelphia politics, though, life appears to be on pause. The city's Democratic Party boss, Bob Brady, has held that job since - are you ready, children? - 1986. You won't find anyone under 40 on City Council. We're 18 months away from the next mayoral vote and political warhorses such as Ed Rendell and Lynne Abraham, septuagenarians both, are still being mentioned as possible candidates.

But paradigm-shifting trends often start with minor events, and the recent awakening of the Graduate Hospital neighborhood's silent millennials might just be the first smoke signals of change. Frustrated by the political elite's car-centric vision, a group of twenty- and thirty-something professionals fielded a slate of 23 candidates in the May primary for the most grassroots of political offices, the Democratic City Committee, in the 30th Ward.

It's been eons since anyone contested such races. Some wards are so safe, committee seats are handed down father to son, mother to daughter. So it was no small surprise when the upstarts took 13 of 34 spots. They also doubled turnout over the 2010 vote, a neat trick considering it was a primary.

What makes this an architecture story is that the challenge was precipitated by several zoning cases that highlighted the city's widening generational divide on urbanist issues such as density, parking, bike lanes, and outdoor dining. TJ Hurst, the resident who organized the political campaign, believes "what's happening in Graduate Hospital is a microcosm of what's happening in Philadelphia."

Despite its generic-sounding name - taken from a hospital that no longer exists - Graduate Hospital is not some soulless place that sprang up yesterday. Located between South Street and Washington Avenue, west of Broad, it is a dense, 19th-century rowhouse neighborhood where African American cultural greats such as singer Marian Anderson and architect Julian Abele nurtured their talents.

Recent arrivals have been mostly white millennials such as Hurst, 29, a Mississippi native who was sent to Philadelphia as an organizer by the 2008 Obama campaign, fell in love with the city, and stayed. But Graduate Hospital has avoided the racial tensions that afflict Point Breeze, the next neighborhood south. (A similar political challenge there led by developer Ori Feibush fizzled.)

As the area has gentrified, Graduate Hospital has become one of the city's most improvement-obsessed neighborhoods, with residents forming nonprofits to support the local school. They've helped create not one but four new parks, including the just-opened Grays Ferry Triangle at 23d and South Streets.

Here the battle lines are more likely to be determined by age. Lately, the disagreements have centered around what you might call sidewalk issues. Should a new restaurant have outdoor tables? How can residents get the city to stop approving garage-fronted rowhouses? What can be done to encourage more corner shops? For millennials, encouraging pedestrian street life and discouraging driving is the key to a lively neighborhood.

The breaking point came in April after the zoning board rejected what seemed like an inoffensive building proposal for a surface lot at 23d and South, an 18-unit apartment house designed by Plumbob's Howard Steinberg. The proposal revealed a clash of cultures between Graduate Hospital's two main civic groups. While the apartment building received a ringing endorsement from the millennial-dominated South of South Neighborhood Association, it was fiercely opposed by the older, more established South Street West Civic Association, which mostly sticks to the area's western end.

It wasn't lost on millennials that South Street West is headed by Barb Failer, who has been a committeeperson for more than two decades. She thought the 46-foot-high building was too big and too dense. But the deal-breaker was the absence of dedicated parking in the building.

Although the apartment house exceeded the height limit by eight feet, South of South's millennials had argued that its site at the prow of the Grays Ferry triangle was a natural spot for a building of such stature. It was virtually the same height as the five-story structure torn down there years ago.

It wasn't the first time that Failer, who is in her mid-50s, and her group had resisted such urbanist notions. South Street West scuttled ground-floor retail at the new Toll project at 24th and South Streets and objected to the park at the Triangle. With the help of ward leader Marcia Wilkof, the group nearly succeeded in barring outdoor tables at Sidecar Bar & Grille on 22d Street.  Wilkof later changed her mind and endorsed the proposal for outdoor dining. (Wilkof declined to be quoted for this column.)

Failer complains that the millennials are too besotted with their big ideas about cities. "They have a macro view of the world," she explains, "while I care about the micro issues," such as whether a new development makes it hard for a home-owner to find a parking space on his block.

Such attitudes rankle the area's newcomers. "We live in a city and this is what you get," argues Matt Olesh, 31, a litigator who moved here in 2007 and won a committee spot. "It's frustrating to see good projects get stifled."

One reason that millennials have a hard time implementing their vision for the city is that, so far, they haven't been regulars at the polls. "Until millennials get above an 8 percent turnout, we don't count," explains Kellan White, 28, a former Graduate Hospital area resident who runs the New Leaders Council, which offers courses in grassroots politics.

Still, Neil Oxman, a veteran Center City political consultant who has run campaigns across the country, including two presidential races, sees something new in the Graduate Hospital committee races. "If millennials could insinuate themselves in politics in the same way they have in nonprofit work and activism, this city would be a lot better off."

Note: This column was updated to remove a reference to former ward leader Terry Gillen. She says she did not particpate in the discussion over Sidecar's outdoor tables. The column also was changed to reflect that ward leader Marcia Wilkof changed her view on outdoor tables, and to change the percentage of electoral participation.

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