THE PROPOSAL to build a $1 billion casino barely a mile south of the District in Prince George’s County — a project tantamount to Las Vegas on the Potomac — is a grandiose grab for easy money. It is the latest symptom of gaming fever gone wild in Maryland, which, having trumpeted the supposed benefits of slot machine parlors only to discover they were badly hyped, is now flirting with the idea of doubling down with a headlong rush into the casino business. It shouldn’t.

The mega-casino, which would be located at National Harbor, the flashy new development near the Woodrow Wilson Bridge, is the brainchild of Prince George’s County Executive Rushern L. Baker III. Mr. Baker, a year into his term, has done a lot to burnish the image of his county after years of graft in high places. But while he is understandably eager to jump-start economic development, a casino on the scale of the Bellagio is not the way to do it.

Mr. Baker’s proposed casino would be one of the biggest gambling venues in the nation outside of Las Vegas or Atlantic City. In his vision, it would be unabashedly upscale — probably prohibitively so for the vast majority of middle-class Prince George’s residents.

In fact, that may be part of the appeal to Mr. Baker, a longtime opponent of slots parlors whose sudden embrace of gambling represents an about-face. Rather than preying on locals who can ill afford the slots and table games at a run-of-the-mill casino, he’d prefer a high-end facility to attract out-of-town conventioneers and well-heeled customers from Virginia and the District.

At the same time, Prince George’s officials propose a tax regime for the casino that they say would spin off $50 million annually for the county to help revive foreclosure-struck neighborhoods, promote developments around Metro stations and funnel to local nonprofits. County officials say that the casino would bring several thousand decent jobs.

Mr. Baker prefers a glitzy gambling mecca at National Harbor to a lesser facility at Rosecroft Raceway, a few miles farther south, whose owners, Penn National Gaming, have been pressing for a casino. He says that if lawmakers in Annapolis don’t adopt his vision — which they’re not likely to, at least this year — he will oppose legislation that would result in a casino at Rosecroft.

The trouble is that gambling is gambling — a poor catalyst for economic development no matter how many bells and whistles come attached to it. Any sizable casino in Prince George’s would rebrand the county, and not for the better. At the very moment that Prince George’s is hoping to attract the FBI’s new national headquarters and to lure major private-sector employers, building a big casino seems like a damaging diversion.

To his credit, Mr. Baker has rejected the idea, pushed by the state Senate president, Thomas V. Mike Miller Jr. (D-Calvert), that gambling revenue is the only way to pay for a new hospital in Prince George’s, which the county badly needs. But in a way he is now advocating something worse — a casino not simply as an unpleasant means to a worthy end but for its own sake. Surely Prince George’s, with its proximity to the nation’s capital, its well-educated residents and its abundance of land available for development, can do better.