Statistics are hard to find, because accident reports often miss the details of where the young people had been and what they had been doing. But Mrs. Grimes recounts one startling statistic, a result of her own research. In 1993, in the westbound lane of the 50-mile stretch of I-10 between her home and Lake Charles, there were 64 accidents in which people 21 or under were injured or killed. All of them involved drinking.

There were only 16 accidents in the same year in the eastbound lane of Interstate 10.

Drinking is almost a point of pride in Louisiana, where young people slurp down Jello shots laced with hard liquor and carry "To Go" cups back to their cars from the bars. New Orleans has drive-up daiquiris.

The liquor lobby is one of the most powerful in the state's government, which explains why the loophole -- as blatant as it was -- took nine years to kill, said Catherine Morgan, the director of victims' services for Mothers Against Drunk Driving in Baton Rouge.

The legal case began last year in Evangeline Parish, when four men challenged the 21-and-over law in the local court. Two of the men, Burke Pierotti and Wendell Manuel, owned bars, and were joined in the lawsuit by Mr. Manuel's son, Jody, and a friend, Stacey Foret, both of whom were under 21.

"I was in the Navy during World War II, in charge of a 31-man gun crew in the Pacific," said Mr. Pierotti, 71, who runs the Kazan Hotel Bar in Mamou. "I had just turned 21 but half my crew was under 21, and when we went back to our home port, those boys couldn't come in a bar with me and have a drink. Well, I believe that if a man is old enough to fight and die for his country, then a bunch of white-haired monkeys in Washington, D.C., got no right to tell him he can't have a drink. And that's how I feel about it."

Mr. Manuel, who runs a bar just a few miles away, said: "We don't want to see anyone killed. They're gonna drink. It's better that they drink inside than in their cars."

Lawyers for the bar owners argued that before the state can discriminate against 18-to-20-year-olds in its effort to reduce drunken driving, it would first have to apply "other non-discriminatory methods, including public education," and allowing a tax credit to retailers to provide free non-alcoholic drinks for designated drivers.