Mr. Washington's opportunity to unite a badly divided city

Much will be expected of Harold Washington as Chicago's first black mayor. But on the heels of a bitter, racially divisive campaign, he also faces some unparalleled opportunities to live up to those high expectations.

A liberal, maverick Democrat, Mr. Washington vowed to rebuild the city and its neighborhoods and to end the political patronage system that has so long dominated Democratic Party politics here.

That pledge of reform was one reason many local Democratic machine leaders defected to GOP candidate Bernard Epton. Many Chicagoans have long been hungry for more stable, open city government that would involve a broader mix of residents on a fairer basis. Many blacks, in particular, who have long supported the Democratic Party here without sharing much in the spoils of power, view Washington's victory as a sort of communal Academy Award for years of paying political dues.

Washington, who has an interracial transition team of top civic and business leaders, has pledged to assemble the best professional talent he can find for his administration. He is sure to be watched closely to see how well he succeeds.

Washington's more immediate task is to calm heightened emotions here and convince residents that they have a universal stake in working as a team, helping one another, to make Chicago a better and stronger city.

Although at times during the campaign the candidate was sharply critical of Chicago (once calling it ''a horrible place to live'') and voiced dire predictions as to the street violence that might break out if he did not win, he is in a strong position now as the city's new leader to set a more positive tone. He is also in a much better position than his opponent would have been to forge a biracial coalition in the city's 50-member, all-Democratic City Council.

Since his victory, Washington has promised ''a new beginning.'' And Chicagoans' increased awareness during the campaign of the need for healing the city's racial divisions could help him get a head start on that job.

Who, really, is Chicago's new mayor?

Short and stocky, Harold Washington has been described as a 24-hour-a-day politician who thrives on work and needs little sleep. He is an omnivorous reader, particularly fond of biographies.

He is from a large family of 11 children and claims that his father - a lawyer, Methodist minister, and Democratic precinct captain - was his only role model. Once divorced, he is currently engaged to Chicago schoolteacher Mary Ella Smith.

Eloquent and witty, he is a graduate of the Chicago public schools (the first such mayoral candidate, he says) and of Northwestern University Law School. He has had experience in all three major levels of government, most recently serving as an Illinois legislator and since 1980 as a US congressman.

Washington's past legal problems, including a conviction for failing to file tax returns and suspension of his law license for failing to perform services for which he was paid, were the central focus of his opponent's campaign. Though of considerable concern to many voters, they did not prove the decisive drawback many had predicted. And the new mayor can conceivably now demonstrate to the satisfaction of all that such past personal troubles will not affect his performance as a public official.

In his new City Hall post Washington moves to the helm of a city 40 percent black and heavily ethnic in its white composition. Top ethnic groups in order of numerical strength in this city of 3 million people: Mexicans, Poles, Germans, and Puerto Ricans. Together they account for about 670,000 residents.

From the administration of outgoing Mayor Jane Byrne, Washington inherits some immediate and significant fiscal problems. The city's budget and those of Chicago's school and transit systems need major infusions. Washington has pledged to cut at least $100 million from city spending to make up for the city's shortfall. He has said one of his first tasks will be to appoint deputy mayors for both management and policy.

In Congress, Washington voted against most social spending cuts and admittedly wants to do far more in jobs and services for Chicagoans than has been done in the past. One of every five city dwellers here lives at or below the federal poverty level. As yet, it is not clear where he will find the added dollars to do what he wants to do. Though he favors a sharp state income tax hike, he is not advocating any increase in city taxes.

Long responsive to the black community's charges of police brutality, he has vowed to draw a new commander from the ranks of the police force and to set up a civilian review board.