Bayview has seen intense gentrification in the past 10 years. This is consistent with national trends -- more affluent Americans are increasingly returning to city cores -- and is, in part, a result of land speculation in anticipation of the redevelopment. According to the San Francisco Chronicle, the median price of a single-family home in Bayview rose from $129,000 in 1996 to $570,000 in 2008, a faster increase than any other neighborhood in the city; some houses on the new light-rail line jumped from $200,000 to $800,000 over the same of the period. (The housing bust erased some of those gains.) Activists like Harrison see these figures as harbingers of what future development will bring. They agree that, in the long term, the project will help revitalize the community -- but what community will be there then?

Despite their determination to maintain neighborhood stability, Kaslofsky and Lawson acknowledge that change is coming. Bayview will not be the same place 20 years from now, they say -- and they insist that's a good thing.

"From my personal perspective," Lawson says, "the real community champions in this neighborhood are the ones who basically focus on, 'I want to be able to raise my kid in this area, and I don't care what has to change to make that happen, I don't want it to stay the way it is.' "

"Invasion and succession -- in planning speak -- is a very natural urban ecological thing."

Of course, how natural it feels depends on which side of the invasion you're on.

Displacement in Bayview today happens in a different way than in the days of the Fillmore. Many Bayview residents live in subsidized housing or own their own homes, so they're not at risk from rising rents. Instead, say Bloom and Harrison, the younger generation is moving out because they can't afford to buy homes. And some longtime homeowners, who waited decades to see their homes appreciate, are now selling. But because what they sell for isn't enough to buy a house elsewhere in San Francisco, they are leaving the city. Only the more affluent can afford to buy in.

Marie Harrison's family is Exhibit A. She owns her home and has raised three children, seven grandchildren and three great-grandchildren in the neighborhood. But when her son and his wife wanted to buy a house, they couldn't afford anything in Bayview. They moved 80 miles away to Stockton, Calif., instead.

In 2000, Bayview was about 48 percent black -- down from 65 percent in 1990. That figure has continued to decline. In 2010, the city as a whole was only 6 percent black, down from 13 percent in 1970. San Francisco lost 10,000 black residents in the last decade; Antioch, an hour inland, gained nearly that many, a 114 percent increase. Many of the Bay Area's outer-ring communities have grown rapidly, attracting lower-income black and Latino residents, who move where their money buys more space while continuing to work in the city. San Francisco isn't alone in this trend. You can find lower-income exurbs growing, says Berkeley professor Hutson, "from Seattle to San Diego."