The Carter campaign in Maryland, which for the past two months has been waged by surrogates and state party officials with sputtering energy and mixed results, finally began in earnest last Monday morning beneath an azure sky in working-class east Balitmore. There, William D. Schaefer, the dour, jowled Democratic mayor, clambered up and down the marble staris of a long line of row houses, rapping his knuckles to get out the vote.

The mayor's field work, which was joined by Sen. Paul Sarbanes and later in the day, by Gov. Harry Hughes, was brief, a staged event for Baltimore television.But it began what all along has been the main effort of the Carter campaign in Maryland and in all likelihood the deciding factory of a close election: getting out the vote in overwhelmingly Democratic, apthetic Baltimore.

With just days left in the campaign, the Carter forces have focused virtually all of their resources on getting voters in Baltimore to the polls next Tuesday. David Doak, the chunky, serious-minded young Arizona lawyer who is running the state Carter campaign, has spent more than $15,000 to print 1.1 million election day sample ballots -- traditionally the grease of Balitmore machine politics -- and invested almost as much in a large phone bank with paid operators. "Getting out the vote in Balitmore is critical," he says. "It will make or break the campaign."

Indeed, even if the Carter campaign had done nothing in the state up until now -- and it has been reasonably visible -- it could probably win the state on the strength of a successful organization effort in Balitmore alone. For in a state where Democrats are three times as numerous as Republicans, Baltimore is the party's mother-lode, the dense tract where an insurmountable margin can be built for almost any Democratic statewide candidate, if only the voters turn out.

"You could be a monkey and run as a Democrat in Balitmore City and win," said an envious Robert Pascal, the Republican Anne Arundel County executive, while compaigning for Reagan yesterday.

In 1976, Carter defeated Gerald Ford in Maryland by swamping him in the city by a margin of about 97,000 votes and falling only 10,000 votes behind in the rest of the state. In particular, Carter captured 80 percent of the vote -- and more than three-quarters of his margin -- in the city's westside 7th Congressional District, which is dominated by black, Jewish, and silkstocking precincts.

This year, city election officials and organization leaders around the city are predicting that Baltimore's overall turnout could be as high as 68 percent, the highest since the 1960 presidential election. There are dissenters from that view, however, and more importantly there are worries among the Democrats that many of their traditional supporters will go to the polls this time and abandon the party candidate.

Carter's campaigners also admit they are in trouble with the middle-class Jewish voters who dominate Baltimore's northwest corner and nearby areas in Baltimore County. A poll released by the area's Jewish Times newspaper yesterday showed Carter ahead of Ronald Reagan by 38 to 17 percent among Jewish voters, but 25 percent were still undecided and independent candidate John Anderson drew 15 percent, well above his current standing in national polls.

In much of the rest of the city, however, the all-important political organizations seem to be doing their best to deliver the Democratic vote. In the black neighborhoods of west Balitmore, where the leading politician, Congressman Parren Mitchell, is working on a national get-out-the-vote drive, the clubs have organized election-day car and van pools to bring out the thousands of voters registered by the Carter campaign and an aggressive NAACP drive in September.

Some Democratic strategists also think that turnout in the black areas may be helped by the city's hotly contested judicial race, which features a well-known black lawyer, William H. Murphy Jr., who has endorsed Carter and is encouraging his constituents to come out and "vote black."

The east and south Baltimore organizations of bosses Joe Bonvegna and Harry McGuirk are also working with more enthusiasm for Carter this year than in 1976, when Carter only narrowly carried the surround 3rd Congressional District by 5,000 votes.

"In '76, see, we took [California gov.] Jerry Brown in the primary, and people weren't as interested in the general," said the moon-faced, cigar-chewing Bonvegna. This year, he said, "we are 100 percent behind the president," mainly because the Carter Administration has sent $2.5 million in federal funds to Bonvegna's neighborhood to help rebuild an industrial park.