First came the blind, then the elderly, then the child-welfare advocates. They made their way today from one legislator to the next, pleading for mercy as the General Assembly began the anguished debate over how to absorb the loss of $300 million in government aid during the next year.

The scene was telling, many legislators observed, since Maryland, with its modest budget surplus and liberal Democratic policymakers, appeared to have weathered the Reagan budget cuts better than most states so far.

"I've talked today to the blind, I've talked to the elderly. They all have the same problem: They say they already aren't getting the services they need, and this is before the really big cuts have hit," said Del. Lucille Maurer (D-Montgomery), an influential fiscal committee member whose office was a prime stopping-off point for the representatives of the needy who filled legislative corridors.

The bulk of the federal cuts in Maryland, as elsewhere, came in health, education and welfare programs, and Gov. Harry Hughes and his cabinet spent much of the fall cutting the 1981-82 budget to make up for the losses. While the state's $150 million budget surplus helped blunt what Hughes' aides call "the cruelest cuts," Hughes still terms the loss of federal aid "potentially catastrophic."

More than 100,000 Marylanders are expected to lose some form of public assistance or food stamp benefits in the next year. Four vocational rehabilitation centers where disabled Marylanders once received training to reenter the job market have been closed, including a Carroll County center that serves portions of Montgomery County. Social workers who assist the elderly and the poor were laid off.

The cuts are still coming almost monthly: Last week 212 state counselors who now help welfare recipients and unemployed Marylanders find jobs received layoff notices--a result of the unexpected loss of $5 million in assistance from the U.S. Department of Labor.

Hughes is to present his 1982-83 budget proposal to the General Assembly on Wednesday, and legislators say they are uneasy about voting on it without knowing how much federal aid to expect. As a precaution, they say they may have to cut deeply into programs that advocacy groups say have already been pared too much.

"What we're trying to guard against is a whopping deficit come July," said Del. Nancy Kopp (D-Montgomery), one of the more liberal members of the House Appropriations Committee. "Things aren't as bad yet in Maryland as they were expected to be, but they are very likely to get worse than anyone expected. There are so many conflicting numbers flying around for our budget cuts that nobody knows what's happening."

The only certainty at this point is that no advocacy group can have everything it wants; groups that once fought together for social service funds are now competing with one another for the little that remains.

"We're in the gruesome business of deciding whether the money ought to go to the very, very poor, or to just the very poor," said Kalman R. (Buzzy) Hettleman, secretary of the state's Department of Human Resources, which lost the most funds of any department.

Although Hughes has earmarked about $13 million of the $150 million state surplus for increases in welfare grants, most of the money, about $100 million, will be used to give state employes a raise. And the surplus will not offset the even bigger federal cutbacks in projects that are near and dear to some of the state's key legislators: subway construction in Montgomery and Prince George's counties and subway construction and the dredging of the harbor in Baltimore.

The Hughes administration has absorbed the federal cuts so far in ways that reflect the state's enduring liberal tradition, even in an era of Reaganomics. For example, when federal regulatory changes dictated that Maryland cut about 30,000 welfare recipients from the rolls, legislators and bureaucrats came up with a novel regulatory change that allowed 3,000 working poor families--about 9,000 people--to continue receiving assistance.

To circumvent the federal regulatory changes, Maryland leaders rewrote certain state welfare regulations. And to pay the bill for the larger rolls, the state DHR, which picks up half the cost of welfare benefits, recycled money saved on the elimination of 20,000 former recipients from the rolls.

In his 1982-83 budget proposal, Hughes has asked the legislature to use the rest of those recycled funds to raise welfare benefits for those remaining on the rolls--an increase from $326 to $355 a month for a family of four. Legislative leaders say they expect the General Assembly to approve the increase, even as they push for more austerity in other areas.

"I think this reflects a Democratic, compassionate look at the impacts we're feeling from the Republican administration in Washington, and an effort to make them as limited as possible," Kopp said.

In education, the state has yet to feel the full impact of the Reagan cuts because it receives federal assistance a year in advance. As a result, the Maryland Education Department in 1981-82 is still drawing on funds appropriated by the Carter administration, and has so far been forced to make major cuts only in three programs--vocational rehabilitation, child nutrition and impact aid. The other cuts will come a year from now, and state officials are still waiting to hear from Congress and Reagan how large they will be.

The loss of impact aid, which is targeted to local school districts with high concentrations of federal employes, has prompted concern that Anne Arundel County, with its large military population, may have to resort to charging fees for certain children in public schools.

The debate between Hughes and the legislature over how to set priorities for program cuts is expected to continue throughout the Reagan era, as Maryland continues to lose federal aid. Many legislators question Hughes' approach of cutting programs across the board in most departments, rather than deciding which programs are most valuable, and attempting to salvage those while eliminating others.

The legislature, under the Maryland constitution, has power only to cut the governor's budget, not to reallocate money between programs. Still, some legislators are considering moves to eliminate certain social service programs that they contend have been cut to the point of ineffectiveness. Among the most vulnerable programs are home care for the elderly, public housing services, grants to social service volunteer agencies and battered spouse programs.

It is this prospect that has set off the competition between groups that used to lobby together for increased government aid to the disadvantaged. A similar competition has begun between local governments for diminishing state aid that has been essential in limiting property tax increases.

Before Reaganomics, said Prince George's County Council President Parris Glendening, "it was sharks swimming around in the water taking what they could get. Now, it's sharks in a frenzy."

But so far, most jurisdictions seem to feel the state has tried hard to make the best of a difficult situation. In the nine months the legislature was out of session, Hughes had to deal with the confusing fiscal 1982 budget situation pretty much on his own, ordering each of his cabinet secretaries to reduce expenditures by 25 percent.

Unlike Virginia, where state Republican leaders have embraced Reagan's economic program as their own, most politicians in Maryland--one of the few states to stick with Jimmy Carter in the last election--have been outspoken in their denunciations of Reagan's budget actions. Hughes told a congressional committee last month that he questioned the "breathtaking, breakneck speed" at which Reagan had decided to apply the brakes on inflation and federal spending.

The legislature will be considering several revenue-raising measures to offset some of the program cuts, but most assembly members are wincing at the idea of running for reelection on the heels of tax increases. Hughes has proposed a tax increase on the wholesale price of gasoline and wants to increase vehicle registration fees, two revenue measures expected to set city, suburban and rural legislators scrambling to divide up the pie.