St. Louis Circuit Court Judge Robert H. Dierker Jr.’s ruling July 2 striking down the redevelopment ordinances for developer Paul McKee’s NorthSide plan was a boon and an affirmation for skeptics. They hardly needed encouragement.

Since the beginning, there’s been plenty of doubt that Mr. McKee’s $8.1 billion, 20-year plan to remake 1,490 acres of mostly blighted land in North St. Louis would get off the drawing board.

We’re talking, after all, about a once-bustling part of the city largely abandoned two generations ago because of white flight and the decline of heavy manufacturing. Nearly half of the development area is vacant land or land occupied by vacant buildings.

Rebuild a large swath of North St. Louis over the next generation?

Build 10,000 new homes, 4.5 million square feet of office space and 1 million square feet of retail development? Make it diverse, power it with green energy, attract major employers as tenants and partners?

It was way too bold for a lot of people, including the judge.

His 51-page opinion drips with incredulity. It implies the political process in the city of St. Louis that led to passing the development ordinances was little more than a farce.

The opinion refers to those who assembled the monumental development proposal as “the usual suspects.” It observes that “the record is bereft of evidence that anyone, anywhere has accomplished the feat of attracting new residents to core urban areas on the scale envisaged” by the developers.

The judge failed to note that the NorthSide vision created unprecedented political consensus in Missouri. A lot of people who don’t ordinarily get along wanted to make it happen.

Mr. McKee is best known for building large commercial projects in the suburbs. He invested millions of dollars of his own money and, over five years, acquired parcels of property and pieced together a development site.

Former Missouri Gov. Matt Blunt, a Republican, convened a special session of the Republican-controlled Missouri Legislature in 2007 to approve a special tax credit for the project. The tax credit supports assembling large tracts of land in distressed urban areas and was enacted with this project in mind.

NorthSide has enjoyed strong support from three African-American aldermen in whose wards the project site lies — even over objections of constituents who justifiably were angered by Mr. McKee’s neglect of properties he had acquired.

The development ordinances struck down by Judge Dierker — including authorization of more than $150 million in tax increment financing for streets, sidewalks, sewers, utilities and other public improvements in two areas of the development site — easily won approval from the St. Louis Board of Aldermen.

The project is touted by both Missouri U.S. senators, Republican Christopher S. “Kit” Bond and Democrat Claire McCaskill. U.S. Housing and Urban Development Secretary Sean Donovan noted their bipartisan support when he visited parts of the NorthSide development site in May.

The first phases of the NorthSide plan focus on commercial sites suited to major new employers. One target area is the land adjacent to the new $670 million Mississippi River Bridge at Cass Avenue, which is scheduled for completion in 2014. The other is land north and west of Union Station — near the terminus of the expected revitalization of the Gateway Mall, within easy reach of  U.S. Highway 40/Interstate 64.

In other words, the NorthSide plan and the process by which it evolved and won converts is a good deal more deliberate and thoughtful than one might suspect when reading the judge’s decision.

What’s more, for all of his personal skepticism about the project (and editorializing about sausage-making parts of the political process), the judge made short work of the legal objections to development ordinances, the only place his opinion really mattered.

He upheld the city’s “blighting” determination, found the financial data and analysis supporting the tax increment financing flawed but legally sufficient, approved the project’s “phased” approach and summarily dismissed a welter of other complaints, large and small.

The flaw was in the technical question of whether the redevelopment plan should have provided detail on specific “projects.”

Even this defect, the judge conceded, might not have been raised in the lawsuit and, in any case, might be cured by further action by the Board of Aldermen.

The judge’s decision on this technical issue has deep political, social and economic implications for St. Louis. It deserves accelerated consideration by an appeals court.

One of the most talked about books in St. Louis is “Mapping Decline” by Colin Gordon, a history professor from the University of Iowa. It is based on a  2008 study and traces the fate of a single property in North St. Louis.

In the process, it exposes with precision St. Louis’ determined and brutal pursuit of racial segregation, and the terrible toll it took.

Some people are willing to close the book on “Mapping Decline” with a shrug. Others want to write a new chapter — reversing history on a grand scale.

NorthSide may well be a long shot, but it is a shot worth taking. It represents an unprecedented opportunity not just to renew what once was a vital part of the city, but also to respond to a terrible wrong wrought by segregation.

NorthSide has had no greater political champion than St. Louis Mayor Francis Slay. For the project to receive a true test in the marketplace and survive the onslaught of naysayers, it will need Mr. Slay’s outspoken support more than ever.