A bill to raise the drinking age in Maryland to 21 now seems virtually assured of passage after the Maryland House of Delegates--under heavy pressure from the public and the political leadership--today rejected a compromise plan to raise the age to 19.

A more restrictive drinking age became one of the General Assembly's chief campaigns as Gov. Harry Hughes, the legislative leadership, school teachers and administrators, the state police, newspaper editorialists, civic activists, and the well-organized Mothers Against Drunk Drivers (MADD) united to make it tougher for young adults to drink.

"No question, the public wants 21," said House Speaker Benjamin L. Cardin after the House vote. "My office got hundreds of phone calls. We were flooded with phone calls--flooded."

The House is scheduled to vote Wednesday on a bill to raise the drinking age to 21. Many of those who fought unsuccessfully today for raising the age limit by one year now say they will agree to raise the age by three years. Currently, 18-year-olds in Maryland can buy beer and wine.

The House rejected the 19-year-old drinking age proposal by a vote of 61 to 77 after intense lobbying by House leaders who asked delegates to uphold the unanimous vote of its own Judiciary Committee. Hughes invited black legislators, the women's caucus, and the chairman of the Prince George's County delegation to his office for some arm-twisting shortly before the vote.

If the 21-year-old drinking age passes the House, as expected, and is then approved by the Senate, it will reverse eight years of liberal drinking laws in Maryland, which began when 18-year-olds won the right to buy and consume beer and wine in public places in 1973. Maryland would join 14 other states that have decided to raise their legal drinking ages.

For Hughes, the vote against 19 was his first key victory of this legislative session. Hughes had come out in favor of raising the drinking age to 21 in last month's State of the State speech and had upped the stakes by personally intervening and lobbying delegates who were leaning towards 19.

"The governor was very persuasive," said Del. Howard P. Rawlings (D-Baltimore), one of the black delegates who met with him an hour before the session opened. "He put his personal prestige on the line on this issue."

"Perhaps the time has come for us to take another look at the question, 'What is adulthood?,' " said Del. Robert Redding, a Democrat and chairman of the Prince George's delegation. "Perhaps now many of the other privileges of 18-year-olds ought to be looked at, like the right to vote and the right to hold office. Many of the things we bestowed upon young people, they are not dealing with responsibly."

Redding met with Hughes on the issue last week, and his support for a drinking age of 21 was a key loss for the Prince George's delegates who took the lead in the fight to peg the age hike at 19. The University of Maryland, with several on-and off-campus drinking spots, is in that county, and many Prince George's bars and liquor stores near the District of Columbia border stand to lose thousands of dollars in business if the age is raised.

The legal drinking age in the District is 18.

The bid to raise the Maryland drinking age by a single year gained momentum last week after several rallies and heavy lobbying by students and tavern owners. But the effort failed in the final hours because of defections by wavering Prince George's delegates and black lawmakers who said they were pressured by Hughes and constituents fed up with traffic deaths caused by drunk drivers.

Del. Gerald Devlin (D-Prince George's), who last week said he supported 19 as the drinking age, switched after a weekend visit to his home district of Bowie, where there have been several alcohol-related automobile fatalities involving young persons in the last few years.

"I had some meetings this weekend with some constituents," Devlin said. "They told me it's got to be 21. And the MADD mothers are very strong in Bowie."

Del. Timothy Maloney (D-Prince George's), one of the leaders of the group favoring 19, was stunned by the last-minute defections. "You gave me your word, Pete," he protested to Rawlings. "Your word means a lot to me."

Rawlings shrugged and replied, "He Hughes put us in a spot."

The vote came after more than an hour of emotional and sometimes humorous debate while legislators on both sides frantically worked the aisles lining up supporters. During the debate, Hughes' lobbyists were on the telephones calling delegates at their desks on the House floor.

"I hope the governor's intervention on this issue does indeed signal a new approach to the legislature," said Del. Dennis C. McCoy (D-Baltimore), chairman of the Baltimore delegation. "The governor is in fact exerting leadership on this issue, and I congratulate him for that."