A proposal to raise the state's legal drinking age to 21 narrowly passed the Maryland Senate today, but the two-vote margin was close enough for opponents to predict cautiously that they could reverse it if the vote were reconsidered Wednesday.

After an hour of debate, the senators approved a 21-year-old drinking age by a vote of 22 to 20, with two senators absent or not voting, and two other senators--both with liquor-related businesses--excusing themselves because of a possible conflict.

After the vote, the bill was put off for a day so that one senator who voted and who owns a tavern could file the proper forms declaring he had no conflict. In the meantime, senators on both sides of the issue said they would work to sway the nonvoting senators while shoring up their wavering supporters.

Aides to Gov. Harry Hughes, who made the higher drinking age a centerpiece of his legislative package, were busy calling senators even before today's session recessed.

"It's too close," said Sen. Rosalie Silber Abrams (D-Baltimore), the majority leader counting the heads for the "21" side.

The House already has passed the same drinking age bill, which would raise Maryland's legal age to 21 for all alcohol. Currently, 18-year-olds can legally drink beer and light wine. Under both the House bill and the Senate version debated today, young people who turn 18 before the bill takes effect July 1 will be allowed to drink.

Senate leaders had agreed to wait until the House voted, to avoid the deadlock between the two chambers that killed previous years' attempts to raise the drinking age.

The opposition to the higher drinking age came mostly from senators from Prince George's County, which stands to lose liquor business money to nearby District of Columbia stores and bars. Prince George's senators argued that a higher Maryland drinking age would cause more highway deaths, as young people drive to Washington, where the drinking age is 18.

"You can start praying if you pass this because you are going to cause a problem on the highways," said Sen. John J. Garrity (D-Prince George's).

Sen. Tommie Broadwater Jr. (D-Prince George's), a tavern owner who voted against raising the age to 21, called alcohol "one of the luxuries of life." He said, "What are you expecting them young people to do to enjoy themselves? We know they're going to drink something, and it's not going to be Coca-Cola."

Besides, Broadwater said, "They're not getting high off the alcohol, they're getting high off the grass." Broadwater later asked that he be allowed time to file a statement declaring that he had no conflict of interest.