ST. LOUIS, April 5 – People here joke that the sidewalks get rolled up at night as workers flee to the suburbs, but through the N.C.A.A. basketball tournament that ended on Monday, the sidewalks got washed instead. St. Louis primped and spruced and papered its empty buildings with signs about the rosy days to come and got its television close-up in front of millions of viewers around the world.

But much of the city’s upbeat message was intended for consumption at home, where urban pioneers like John and Mary Kelly have staked their fortunes on making the renaissance real. The couple opened Kelly’s Deli four years ago on what was then a nearly abandoned block of downtown, and they still have great expectations because of the conversion of vacant buildings into loft-style apartments in their neighborhood and the escalating real-estate prices that are drawing investors.

But for St. Louis, which lost half its population in the decades after World War II, and for the Kellys, the good times still remain mostly unrealized. The basketball crowds gave a nice jolt to the cash register, they said. And the event put as much as $60 million into the local economy over four days of revelry, economic development officials said. But by Tuesday it was business as usual.

“I don’t know how long we can hold on,” Mr. Kelly said.

The calculus of rehabilitating any wounded city is partly about experimenting until something that works is found. St. Louis is pinning its hopes on architecture, specifically its stock of glorious old buildings that now stand like monuments to a vanished economy of manufacturing might. But selling the portrait of that recovery, city officials and development leaders say, is complicated by history and myth and the deep divisions in Missouri politics, and to a certain extent by the even trickier terrain of sexual orientation.

The city is an island of Democratic voters in a sea of increasingly conservative rural and suburban ones. It suffers from a reputation as a dangerous place, which tends to keep many outsiders from venturing in. And the recovery effort has partly been led by members of a group that is not popular in many parts of Missouri: gay men and lesbians who have renovated neighborhoods and opened new businesses in recent years.

In August, voters across the state overwhelming voted yes on an amendment to the State Constitution banning same-sex marriage. St. Louis, in a lonely dissent, voted no.

The city’s population, which was more than 850,000 in 1950, had fallen to 348,000 people by 2000, with many of those who left now living in the city’s ring of suburbs.