Hyman Pressman, the flamboyant controller of Baltimore City, spent the opening day of the Democratic National Convention here shouting his contempt for President Carter at every available caucus and distributing wooden nickels bearing the legend "Value of the Carter Nomination."

Although these lobbying efforts might have been appreciated by campaigners for Sen. Edward M. Kennedy, there was no particular reason for Pressman to work so hard. In fact, there was really no reason for Pressman to be here. He is not a delegate or even an alternate. He has no official role in any presidential platform or lobbying campaign.

Nevertheless, Pressman and at least half a dozen other state party warhorses and officials are here in New York this week, hanging onto a Maryland delegation that excluded them with reform-oriented selection procedures and minority quotas.

Instead of brokering votes they might have commanded a decade ago, Pressman and his outcast political colleagues have spent their time begging for floor passes from friends, staking out hospitality suites and attempting to lobby delegates who have no obligation to listen to them.

"They're our groupies now," said Leonard Lucchi, a Young Democrats leader from Bowie who took advantage of the changes in party rules to win a seat as a Kennedy alternate. "I prefer to see it this way. We have a more diverse delegation, and everybody has an equal voice."

Some of the more porminent hangers-on in Maryland, including Baltimore Mayor William D. Schaeffer and Baltimore County Executive Donald Hutchinson, say they deliberately refrained from running for seats at the convention "to give others a chance." Both Schaffer and Hutchinson were here Monday for a convention rules committee meeting, then decided to stick around to watch the show.

Others, like Montgomery County State Senator Laurence Levitan, Baltimore ward boss Clarence (Du) Burns and Baltimore State Del. John Pica, tried and failed to win delegate seats.

"I wanted to be a delegate and come to the convention," said Levitan, a powerful committee chairman in Annapolis. "But that selection system is so crazy -- it's just too much to go through."

Forty-one of Maryland's 59 delegates were selected at caucuses in June, under tight rules that specified not only how many caucuses in June, under tight rules that specified not only how many Carter and Kennedy delegates could come from each congressional district, but how many had to be women.

Getting elected depended less on political power or name recognition than it did on sex, race, or the ability to bring 75 or more supporters to a Saturday afternoon meeting.

Thus, teacher Paul Yorkis of Joppa, for example, was able to beat out former U.S. Sen. Joseph Tydings Jr. and one of Maryland's most popular state senators, Frederick Malkus, for his slot as a Carter delegate. p

"I had a lifelong ambition to run for office and now I've fulfilled it," said Yorkis, who distributed thousands of flyers before the delegate caucuses to win election. "Now I'll probably get out of the system."

The Democratic Party left 18 of Maryland's delegate slots as at-large positions, and more than a dozen elected officials and party leaders used those places to get on the convention floor.

But with people like Yorkis making up much of the rest of the state group, dozens of other traditional eaders have been left with nothing to do, even if they came along in hope of getting in on events.

Schaefer and Hutchinson found some work to do on the convention floor Monday night when Maryland Carter coordeinator Ed Crawford turned to them to help keep Carter delegated in line for the crucial "open" convention rules vote.

That task was not particularly long or difficult, however -- all of Maryland's Carter delegates stayed firm on the rule -- and by this morning Schaefer found himself standing in the lobby of the Holiday Inn Coliseum, where the state delegation is staying, with very little to do.

"I decided to come up here at the last minute, and didn't plan much, Schaefer said. "I'd like to go to the Picasso exhibit [at the Museum of Modern Art] but I couldn't get a ticket. I'm just waiting for the acceptance speech Thursday night -- that's the only reason I'm here now."

Levitan, who also arrived in New York on short notice, wasn't sure at first whether he would be able to get into the convention or even find a hotel room. Monday night, however, he made his way to the Maryland signpost on the convention floor.

"I'm doing real well," he said cheerfully. "I got use of a floor pass and found an empty hotel room. I even got passes to the covention VIP room. All I need now is a place to sit down -- there's no extra chairs here with the delegation."

Not all in Maryland's delegation were pleased with their unofficial helpers. "They're a pain in the - - -, really," said one delegation official privately. "They're so concerned about being important, they keep sending us around to find new credentials and passes for them, and they aren't doing around to find new credentials and passes for them, and they aren't doing anything here."

But at least one of the hangers-on has managed to have a real impact on several delegates. Burns, the East Baltimore ward boss, handpicked two lieutenants from his organization to push for delegates when he realized he might not be able to win because of selection rules. Both delegates say they are loyal to Burns.

"Du is my mentor," said Carolyn Stith. "I've been tagging along behind him for 10 years. I talked over the votes with him before I came here." Stith's colleague, Nathaniel McFadden, also a Carter delegate, said he, too is beholden to Burns.

"Du came here with us to take in the atmosphere," said Stith. "He sat in the gallery last night, but he said he couldn't see well enough from there. He's saving his influence to get himself down here on the floor Wednesday night."