Friday night in Georgetown, and the line for Winston's stretches down M Street, nearly merging with the crowd in front of the Crazy Horse down the block. Shelly Fabian and her friends from South River High School in Annapolis, waiting patiently to get inside, have raised the art of District bar-hopping to a science: once a month, 10 of them pile into a van and drive 40 miles to drink legally.

"You can go out and get drunk in Annapolis if you want to -- buy beer and go to somebody's house and get wasted," said Fabian, 18, a silver orthodontic wire girding her front teeth. But, she added, the District "is the place to meet people. It's the only place you can dance."

The District, said Dave Zech, 19, on his way to Bojangles' bar with three friends from Vienna, "is one of the last refuges."

If that's the case, it's a refuge under siege. The District, which permits 18-to-20-year-olds to drink beer and wine but not hard liquor, is the target of mounting pressure from the suburbs to raise its drinking age to 21.

Last week Reps. Frank Wolf (R-Va.) and Steny Hoyer (D-Md.), in their first budget hearing as members of the House Appropriations subcomittee on the District, pressed Mayor Marion Barry to support a higher drinking age. The same day, the board of directors of the Metropolitan Washington Council of Governments passed a resolution with the same objective.

But change is by no means a sure thing. While legislation to raise the drinking age is pending before the City Council, it has elicited no groundswell of support and is not expected to pass this year.

The suburbs are not the only source of pressure for a higher drinking age.

The District also faces an "incentive" program, enacted by Congress last year, under which states that fail to raise their drinking ages to 21 will lose 5 percent of their federal highway funds if the laws are not enacted by October 1986, and 10 percent if they are not in place by October 1987. The National Highway Traffic Safety Administration (NHTSA) estimates that the District faces a loss of $2,486,000 in fiscal year 1987 and $4,972,000 in fiscal year 1988 if it does not change its law.

Since it was adopted last June, the program has already had its desired effect on six states, including Virginia, where the General Assembly this year voted to raise the drinking age to 20 in 1986 and 21 in 1987. The drinking age is currently 19 for beer and 21 for wine and hard liquor.

A total of 30 states currently restrict alcohol to those 21 or older, and 10 others are considering such laws, according to NHTSA. In 1982, before the federal campaign, Maryland voted to raise its drinking age for beer and wine, which was then 18. As of July 1, the drinking age for all alcohol will be 21; at present, under terms of the legislation, those born before July 1, 1964, are permitted to drink beer and wine.

In the District, council member John Wilson (D-Ward 2) for the second year in a row has introduced a bill to raise the drinking age to 21 for all alcoholic beverages, largely in response to complaints from his constituents in Georgetown and Dupont Circle. Only one other council member, Hilda Mason (Statehood-At Large), has cosponsored the measure, and an aide to Wilson conceded yesterday that there isn't a lot of support for enactment this year.

"Some council members feel that just because Maryland and Virginia did it raised the drinking age , that doesn't mean we will," the aide said. "A lot of people see it as a home rule issue."

Barry has not yet taken a position on the issue.

Meanwhile, concern over street crime and rowdy partying in Georgetown has prompted some bar owners there to hoist drinking ages on their own. Within the last two weeks, the Third Edition and the Fish Market have decided to serve drinks only to customers over 21.

"The mayor's office is cracking down on the kids, and rather than fight everyone we decided to join them in trying to upgrade some of the rowdiness," said Carol Huebner of the Fish Market, which had been a haven for teen-aged partiers.

Likewise, the Georgetown Business and Professional Association, which testified against an increase when the City Council pondered the move in 1983, last month voted in favor of raising the age to 21.

Proponents of higher drinking ages complain that, as drinking ages are raised in neighboring jurisdictions, the District's looser liquor laws are increasingly drawing youths from Maryland and Virginia, who flock to bars in Georgetown and downtown D.C. and -- at times -- drive home drunk.

"If the District has a drinking age which is lower than the surrounding jurisdictions it is going to act as a natural magnet and can cause unnecessary driving and unnecessary risk of exposure -- not only for the younger citizens but for the population as a whole," said Peter J. Larkin, director of Arlington County's Alcohol Safety Action Program and vice chairman of the Washington Regional Alcohol Program.

The result, critics of the District's current law contend, will be a "blood border" of fatal accidents between the District and surrounding jurisdictions.

"The District could become a very attractive oasis, and that could really be a problem," warned NHTSA Administrator Diane Steed.

She cited a study of alcohol-related accidents near the borders of New York, where the drinking age is 19, with New Jersey and Pennsylvania, where drinkers must be 21: 39 percent of New Jersey drivers involved in such accidents and 49 percent of Pennsylvania drivers were under 21.

But opponents of an increase in the drinking age argue that it would unfairly penalize young people and severely hurt local businesses, resulting in a drop in tax revenues without improving safety.

"We're unalterably opposed to any increase in the drinking age," said Michael A. Maher, executive director of the Washington D.C. Restaurant and Beverage Association. "It's unnecessary in the District, unfair, and would produce absolutely disastrous results for our industry."

The industry group estimates that the District would lose $6 million yearly in sales tax revenue alone if a higher drinking age were enacted, plus additional losses in property and income taxes -- far more than the potential loss in highway funds. The burden on District restaurant and bar owners, Maher said, will be greater than on those in other states because of the large population of college-age students here.

"It would probably put us out of business," said Jeffrey Edwards, owner of the 21st Amendment near George Washington University. "It would be real tight" without the 18-to-20-year-old crowd that accounts for about 40 percent of his customers.

Maher said that economics is not his only concern. "This group simply does not deserve to be singled out for selective prohibition," he said. "The 21-24-year-old age group is statistically the worst."

But backers of higher drinking ages point to an NHTSA study showing that those under 21 are more likely to be involved in fatal crashes when the number of miles they drive is taken into account: 18-20-year-olds experienced a rate of 2.9 drunk driving deaths per 100 million miles driven, compared with a rate of 2.4 for 21-24-year-olds, and 1.6 for 25-29-year-olds.

In the Washington area, under-21 drivers, who make up 10 percent of the licensed drivers, accounted for 23 percent of the alcohol-related fatalities, according to figures compiled by the Washington Regional Alcohol Program.

"With the young kid, you have an inexperienced driver who has not built up the degree of familiarity with the control of a motor vehicle . . . and you have frequently an inexperienced drinker for whom very slight quantities of alchohol can have a very impairing effect," said Larkin. "Given those two mixed together it can be very dangerous."

Staff writer Eric Pianin contributed to this report.