Within the classic, old building that houses the governnment of this deeply Democratic city, some curious movements are afoot. Mayor William Donald Schaefer, one of former president Jimmy Carter's biggest supporters, a man Carter recently called "my favorite mayor," is in effect putting out a welcome mat with Ronald Reagan's name on it.

Within weeks after his election, Reagan and his transition team received a supportive, if gently prodding, 26-page document from Schaefer, suggesting outlines for the new administration's urban policy, and volunteering Baltimore as a "laboratory city" for all of Reagan's programs.

Even before the election, while Schaefer was out campaigning for Carter, the mayor quietly mobilized his top staff into an "Enterprise Zone Task Force," charged with learning everything there was to know about these so-called zones that Reagan cited in speech after speech as the centerpiece of his approach to urban blight.

The task force has met several times a week ever since, sometimes with Reagan advisers, and is pusing hard to have Park Circle, a depressed slice of inner city Baltimore, reborn as America's first Enterprise Zone, a national model of Republicanism at work.

Baltimore's whirlwind Reagan courtship is not as out of step as it might seem for a city that voted 3 to 1 for Carter last November. Rather, it is consistent with this city's style, personified by Schaefer since his election in 1975, but going back to the 1950s, as a cunning hustler for federal dollars and for high-profile experiments with federal programs.

"The city is our number one concern.We're into pragmatism first and politics second," one of Schaefers's high-ranking aides explained, as he discussed Baltimore's 26-page urban policy white paper.

Beneath their protestations of optimism, though, Baltimore's leaders are no different from leaders of most other major East Coast cities in these early days of the Reagan presidency in one respect. They are scared.

Under Carter, major cities like Baltimore with high concentrations of poverty and unemployment stood at the heart of federal urban policy, which targeted money, programs and executive orders at so-called "distressed cities." tBy contrast, Reagan, based on his campaign rhetoric, promises a more spartan federal presence in the cities, and a likely end to many Carter policies that favored distressed cities over surrounding suburbs.

What happens in Baltimore in the next four years will be in many ways a test of Reagan's urban agenda, as well as a test for America's major distressed cities. For Reagan vowed during the campaign that his laissez-faire policies would ultimately help cities far more than Carter's interventionist style.

For Baltimore, the uncertainty is compounded; in addition to enjoying the programs and attention that the last four years brought to dozens of urban areas, Baltimore had a rare closeness with the White House that practically no city could duplicate in the Reagan era.

Robert Embry, Schaefer's commissioner of housing and community development, was tapped by Carter in 1976 to preside over those programs at a federal level as assistant secretary of the U.S. Department of Housing and Urban Development. Embry also had a key position on the task force that fashioned the administration's overall urban policy -- the first time a president had put all programs affecting the cities under one umbrella -- and headed a newborn Office of Urban Policy that had a check on the projects of all federal agencies to insure that they worked to aid, or at least not to hurt, central cities.

The city had additional access through other local officials who have longstanding national reputations in their fields, particularly in Democratic circles. For example, Marion Pines, the head of Baltimore's manpower program, has been nationally known in the job training field since the Johnson administration, and was invited to the White House as an adviser when Carter's aides were divising new urban programs.

Baltimore's bonds with the White House were especially evident at one of the farewell White House dinnners that Carter and his wife, Rosalynn, gave earlier this month for close associates. Schaefer, one of the honored guests, was greeted by Carter with a hearty handclasp and the salutation: "There's my favorite mayor." He was seated beside the First Lady.

By contrast, Schaefer did not make the much longer guest list at Reagan's inaugural festivities, even though New York Mayor Ed Kock -- who, in a controversial move during the campaign, invited then-candidate Reagan to his city -- was included.

Around Baltimore City Hall, Schaefer's top aides make light of Carter's "favorite mayor" remark. "I bet he said that to all the mayors," one aide said. But the legacy of the Carter administration's urban policy in Baltimore is undeninable. Several buildings stand out of the city's skyline as clear signs of projects that probably would not have been started if the federal government had not stepped in at cruicial moments in the last four years.

Downtown, there is the Hyatt Regency hotel, the foundation of the city's acclaimed "harborplace" development, funded in part by a $10-million federal grant that was one of the first awarded under Carter's Urban Development Action Grant program (UDAG), which was created in 1978 to stimulate private development projects by helping to pay for necessary municipal improvements and other development costs.

Around the city's harbor, buildozers can be seen beginning construction on the $600-million Fort McHenry interstate highway tunnel that the Carter administration allocated $400 million for, including $100 million out of the $500 million in discretionary funds the Department of Transportation had to distribute nationwide; and boards can be found covering downtown intersections where federal funds are paying 80 percent of the cost of Baltimore's new subway, now scheduled to open next year.

There is the city's new World Trade Center, which was helped along by a $3.5-million federal grant for a parking garage and pedestrain bridges; and its General Motors plant, which was able to revamp for the production of small cars and avoid laying off workers with a $9.1-million dose of Carter dollars.

Much of the money that funded these projects and new industrial parks, arts programs, and youth training centers elsewhere in the city was not even the standard largesse of federal departments to the cities. Baltimore got hundreds of millions in special, discretionary grants allocated by cabinet secretaries to a selected list of mayors; or won the right to host model versions of new federal programs, like the youth employment initiatives program that last year gave the city millions to train disadvantaged youths.

And even in mainline federal programs like UDAG, Baltimore was near the top of the funding list. By the end of the Carter administration, the city had gotten well over $40 million in such grants -- including four contracts worth some $2.8 million just days before Carter left office -- and ranked fourth in the list of cities receiving these funds.

Overall, Baltimore has $258 million in federal grants in its current budget, or 19.3 percent of the $1.3-billion budget total, not to mention $24.7 million in federal revenue sharing funds. And because the city's property tax rate is already at least twice as high as any neighboring suburban jurisdiction, Schaefer and other city officials maintain that most cuts in federal aid could not be made up anywhere else.

Several city officials pointed out that his special status of Baltimore in the corridors of the federal bureaucracy was hardly inaugurated with the Carter administration. "We were special under Nixon and Ford, too," said City Council President Walter Orlinsky, a frequent critic of both Carter and Schaefer. "Baltimore was the place for Republicans to prove that they cared; whenever there was a model program they always wanted Baltimore to be part of the package. Because our programs work well, we don't fight over them, nobody gets indicted, and the cabinet people can come out here and point at us and say, 'here is a good federal program that shows we care."

Still, city officials say that Baltimore never before had such dependable personal and political connections as it did to the Carter administration. Embrey and Carter's fondness for Schaefer was not the only links; there was Jack Watson, Carter's liaison to the cities, who early on became friends with Schaefer and several times went out of his way to see that Baltimore got what it wanted.

The relationship began with the old federal post office in downtown Baltimore, which the city had used for office space and wanted to buy it until it became embroiled in a dispute with the General Services Administration. Schaefer went to see Watson about it late on a Friday afternoon in 1977, and as the mayor tells it "he picked up the phone and by the time I got over to GSA, all the top people were there to meet with me and were ready to do whatever we wanted." The city ended up buying the post office from GSA for $1.

More recently, Watson intervened to help locate the headquarters of the Health Care Financing Administration, now spread through half a dozen buildings in suburban Baltimore County, in the heart of the city's Lexington Market, the focus of another major redevelopment effort.

The campaign to move the agency's headquarters in fact was a model of how Baltimore could influence the Carter administration. Schaefer first proposed the move to Embry, selling it as a model of what could be done nationwide. Then both Embry and city officials met with Health and Human Services Pat Harris and GSA officials to promote the change.

Finally, Watson got a White House letter to the GSA on the subject, and by the time he left office he had persuaded GSA officials to move the headquarters to what is now a vacant lot near Lexington market, where city officials hoped to have a private developer build an office building -- perhaps with another UDAG grant -- that could be leased to the health administration.

But the new headquarters didn't quite get through all the necessary congressional approvals last year, and so now city officials will have to resell the idea to the new Reagan administration and the new Republican leaders in the Senate.

The concern of the city's leaders over the fate of this building now mirrors their anxiety over their developing relationship, or lack of one, with the Reagan administration. The impetus for the move, after all, came from an exceutive order by Carter saying that federal headquarters should relocate in downtown areas when possible. Reagan could wipe out all incentive for action, and the plans for Lexington Market, by simply canceling the order.

And so far, Schaefer, who has never met Reagan, has nobody he can call about this prized project. "We haven't met with whoever -- whoever in the White House will be the top man for us," he says. "We've invited them to come over here and see what we've done. They haven't come yet, but I don't expect them to come right away.

"They have to sit and figure about it. They have to look at us and say, 'what should we go over there for, what is going to happen when we get there, what are they going to try go do to us when we get there,' and so on. We can just hope that they will eventually come over and we'll have the input that we did before."

The Reagan adminstration has more to look at than the vacant lot in Lexington Market, too. Currently, Baltimore has more than a dozen new applications pending at HUD for UDAG grants and loans, and the DAG program itself is funded only through the end of the fiscal year in June, with continuation still an open question.

Already, city officials have been warned about possible cuts in job programs. The public service employment budget for the Comprehensive Employment Training Act (CETA) program has been cut from $17.2 million to $11 million, the equivalent of 600 jobs. Baltimore also has received $55 million, the most in the country, to fund 18,000 youths enrolled in its model emloyment inventive program. If Reagan halts it, even to start a similar new program, "that would mean dismantling this massive program that we spent several years fine tuning, and going back to start from scratch," said Steve Kaiser of the city's manpower office.

Baltimore will also be competing this year for over $70 million in construction money to build the next six-mile segment of the subway system; the Carter administration approved it but Reagan appointees must now appropriate the money. At least $200 million more is needed for the Fort McHenry tunnel, and the city hopes $300 million will be in the Corps of Engineers next budget to begin dredging the Baltimore harbor, the first priority of the city's business community.

"These things will probably get through, but they could be slowed down considerably," said David Falk, the head of Baltimore's liaison office in Washington. "We don't expect to see anything get cut off, but over the course of the year programs could be reshaped. And getting new things is going to be tough."

Embry, who returned to his native city last week as a private citizen, said he is not hopeful for the progress of cities like Baltimore in the next four years, but added: "The government makes a difference, but how big a difference is something you can't quantify without looking at a specific project. You can look at that Hyatt Regency [in the harbor] when it opens, and you know how many people work there, and how much it pays in taxes . . . But you don't know what would have happened if it hadn't been built, what might have been built there instead." CAPTION: Pictures 1 and 2, Baltimore's inner harbor by Bob Willis; Reagan by John McDonnell -- The Washington Post; Pictures 3 and 4, Schaefer by Lucian Perkins -- The Washington Post; Carter by Ellsworth Davis -- The Washington Post; Picture 5, Diners in Baltimore's newly developed Harborplace, funded in part by a $10-million federal grant awarded under Carter. By Gerald Martineau -- The Washington Post