Few expected Baltimore Mayor William Donald Schaefer to lose his bid for a fourth term against the challenge of former Circuit Court judge William H. Murphy Jr. But even fewer expected him to roll up as much as 72 percent of the vote against a black opponent with major black backing around the country in a city that is 60 percent black.

Murphy had hoped throughout the summer he would win 80 percent of the black vote. He had hoped that last year's state's attorney's race was a sign the city's blacks had arrived as a major force at the polls. In that election, the winning candidate, black attorney Kurt L. Schmoke, had whipped white incumbent William A. Swisher.

Murphy was correct: Baltimore's blacks have arrived as a major force. They voted in large numbers last week. They had a major say in the outcome. And what they said was significant not only for Baltimore.

What Baltimore's black voters said in giving Schaefer about 50 percent of their votes was this: Don't come to us and say "Vote for me because I'm black."

That was Murphy's basic pitch throughout the summer. He insisted that Schaefer had been a good mayor for whites and a poor one for blacks.

Black voters listened to that, listened to the big names imported by Murphy--none of whom said anything more than "It's time for a change"--and rejected Murphy.

Baltimore reporters who took to the streets to do informal polling during the campaign's final weeks were amazed to find that a majority of the blacks they spoke to seemed to favor Schaefer. Many believed Schaefer had done a good job, not just in getting glitzy Harborplace built, but in their neighborhoods. They subscribed to the basic theory of politics, "Why fix it if it ain't broke?"

Murphy didn't count on that kind of sophistication. But Baltimore's black voters are not new to politics; they have played an active role for years. They are organized, they know how to play politics and, as they have shown for the past two years, when an election interests them, they vote.

The difference between this race and last year's Swisher-Schmoke race is best summed up in something said last spring by that sage of city politics, Del. Paul E. Weisengoff. Puffing on a cigar in the dark cool of a downtown restaurant, Weisengoff--in May--predicted Schaefer would get 65 percent of the vote.

"Don Schaefer's not Bill Swisher and Billy Murphy's not Kurt Schmoke," Weisengoff said with a shrug. In short, Swisher was a man who had angered the black community with loud rhetoric that had given him the image of a red neck. Kurt Schmoke had all the credentials one could want for a prosecutor's job: He is articulate, Harvard-educated and a former member of a top law firm.

By contrast, Schaefer is a man with considerable black support. He was endorsed by many of the city's top black politicians and he could say time and again that he had been to the neighborhoods throughout his 12 years in office. Murphy, even putting aside the financial embarrassments that plagued him all summer, could give no credible reason beyond, "it's time for a change," that people should vote for him.

Thus, the tremendous effort made by the Murphy people to get blacks registered and to the polls did not produce the expected result. What this means for the city's future is encouraging.

It means that black-white races do not have to break down along racial lines. It also probably proves that blacks are more willing to cross racial lines if they believe a white candidate is better qualified than a black candidate. Although Schmoke did well enough to win with white voters a year ago, he did not do as well as Schaefer did among blacks.

In the long run, what the election probably did more than anything is reinforce the notion that the city's black voters are a force to be reckoned with. Politicians organizing a statewide campaigns in the city are going to have to show blacks there is reason to vote for them.

As Del. Larry Young put it last winter, "We aren't just going to be asking for promises in the future, we're going to be asking for a past record."