If I were trying to sell the Brooklyn Bridge, my list of hot prospects would be headed by Mayor Marion Barry and the D.C. City Council.

I'd tell them what a great tourist attraction it would be, tantalize 'em with the prospect of economic growth for the District, toss some bones to their political cronies and top off the deal with the magical mantra: new jobs.

If you don't think the District government would buy that, you haven't been paying close attention to what our elected leaders have been up to lately.

Anybody who would bite on the blue-sky promises made by the people who got the D.C. cable television franchise and the promoters of Techworld probably would figure that buying the Brooklyn Bridge was as good a deal as putting your life savings in a Maryland savings and loan.

Ordinarily, I consider it tacky for people who write columns to quote themselves, but this is summer, season of the reruns, and if the television networks and Art Buchwald can get away with repeating themselves, surely I can make readers recall a couple of previously penned paragraphs.

"The D.C. cable contract is a boondoggle-aborning," I warned a year or so ago. "There's only one thing wrong with the deal the District of Columbia has made to give developer Giuseppe Cecchi special incentives to build a high-technology exhibit center called Techworld. Techworld doesn't have to be a high-tech exhibit center."

Well, guess what happened? The cable deal is proving to be the District's biggest embarrassment since Bates Street, and Techworld, fortunately, is dead in the water because the developer refuses to promise the building will be used as a tech-mart.

You didn't have to be John Naisbitt or Bob Dylan to see which way these mega-winds were blowing. The hot air and blue smoke were billowing up the stairs of the District building, intoxicating city officials like so much marijuana.

If only the explanation for why D.C. officials were so willing to swallow these fairy tales were so simple. For the best of reasons, District officials wanted to believe what they were told by the promoters of these two ventures. The city ought to be encouraging economic development, Washington needs jobs, and we badly need to compensate for 200 years of racism by encouraging minority enterprises.

But the jobs promised by Techworld were no justification for throwing out the city plan, building a private bridge over Eighth Street NW and giving the developer millions of dollars worth of special favors. Nor was the likelihood that local entrepreneurs could deliver the cable system they promised great enough to justify the gamble of giving them the job.

As a result, the city now is going to have to make some hard decisions on both projects. Fortunately, that gives city officials a chance to salvage their credibility along with the projects.

In the case of Techworld, developer Cecchi has made the decision easy. He said last week that if the city isn't willing to grant special favors for his planned development, he will revert to "matter of right" zoning. That means building a conventional office building and hotel on his two-block site east of the D.C. Convention Center.

There's nothing wrong with that. In fact, it's probably better than Techworld.

You could argue that the city will get fewer jobs, because the building will be smaller, but it really doesn't matter whether you stack more offices on that block or put them on one of the dozens of vacant parcels in the neighborhood. Yes, development of the site might be delayed, but that's because there's a substantial supply of vacant office space downtown.

The D.C. Convention Center unquestionably would draw more business if there were a high-tech trade mart across the street, but nothing in the present zoning law precludes building the mart. If Cecchi's Techworld turns out to be just another office building, it will not be the city's fault. It will be because Cecchi has assessed the market and decided there is no great demand for such a facility. The slow start of similiar facilities in Boston and Dallas is a pretty good clue as to why Cecchi says he can't give ironclad promises to build a trade mart.

Thus the District has little to lose if we get tough with Techmart.

Nor do we have much to lose by throwing out the cable TV contract with DCI and starting over again.

Rather than being remembered as the last city to become mired in a politically tainted TV boondoggle, Washington could be the first city to recognize cable TV for what it is -- a business.

Fed up with the games local politicians around the country have played with cable deals, Congress effectively has deregulated the business, severely limiting all cities' efforts to extract payola from cable companies.

Why shouldn't the District simply set minimum standards for cable TV service and auction the franchise off to the highest bidder? That shouldn't be too hard or take too long. It's certainly more fair and logical than negotiating a new deal with an outfit that lied to get the job in the first place.

There are a few simple demands the city ought to make of a cable contractor. Cable TV ought to be available to anyone who wants it. The whole city ought to be wired within a reasonable period of time -- say, three years. There ought to be enough channels to carry a variety of programs -- 50 is probably plenty. The city's standard provisions for minority participation in contracts ought to be followed.

Beyond those minimum standards, bidders ought to compete on the one basis that is clearly understood by everybody -- cash money.

Instead of turning the cable contract into an exercise in social engineering, we could make it an example of economic realism. That would do more to enhance the District's reputation in the business world than anything else the city government could do.