When Congressman Major Owens signs onto a lawsuit against the mayor of New York in an effort to block a homeless shelter, it tends to catch the eye. Mr. Owens, who first entered public life more than three decades ago as the manager of Mayor Lindsay’s ill-fated anti-poverty programs, is nobody’s conservative. But the city’s proposal to build a shelter for 94 homeless families at Prospect Heights, Brooklyn has brought even lifelong liberal politicians to the brink of sanity. After years of contentedly sacrificing the property values of middle-class homeowners on the altar of social engineering, elected Democrats appear to have gotten the message: don’t kill prosperity.

We sympathize with Mr. Bloomberg, who generally deserves congratulations for attacking the city’s toughest problems with thoughtfulness, nerve, and an admirable disdain for political niceties. But the proposed Prospect Heights shelter — like the administration’s policy in general regarding help for the homeless — has all the flaws to be expected when a tricky job is rushed. Democrats may have learned Lindsay’s lesson, but our new Republican mayor, for all his success, seems to have a ways to go.

Prospect Heights, separated from Park Slope by Flatbush Avenue, has seen a renaissance in recent years that reminds us of its neighboring neighborhood’s development over the last 20 years. Families and young professionals have been flocking to the area in droves, attracted in no small part by the chance to buy homes and put down roots. Suddenly dropping 94 homeless families in the midst of such an emerging neighborhood sends a signal that these strivers don’t like. The only positive development to emerge from the mayor’s shelter ambush is that it has helped catalyze the fledgling neighborhood’s sense of itself as a community, as citizens have met with one another and found a shared sense of the area they would like to live in and the threats to that neighborhood. They have also met with their elected officials and one can see democracy coming alive.

The problem seems to be not only the mayor’s haste, but his utopian claims of fairness — that a shelter is as likely to appear at, say, the Upper East Side, as it is at Fort Greene. Judging from the neighborhoods affected to present, such a claim has had the consequence of ending up with shelters placed in neighborhoods full of new property owners eager to improve their surroundings but not yet politically powerful enough to ward off government projects intended for them. Prospect Heights — along with Jackson Heights and Fort Greene, which are facing similar new shelters — is a neighborhood on the make, but not made yet.

Mayor Bloomberg blundered by failing to at least have met with Rep. Owens and other local elected officials before springing a surprise on them in the closing weeks of an election season, if for no other reason than to avoid the litigation in which the city now finds itself. Instead of planning solutions to the housing problem, City Hall will now have to plan legal strategy. Meantime the left-right politics of this issue are turning around, with poorer neighborhoods discovering that liberal paternalism may not be in their interest after all.