As the Maryland gubernatorial primary races draw to a close with the election Tuesday, the presumptions with which they began six months ago have not been shaken: Democratic Gov. Harry Hughes and Republican Robert A. Pascal, the overwhelming favorites, are expected to win easy victories and face each other in the November general election.

Barring a miracle that would overshadow Hughes' stunning 1978 primary upset, Baltimore State Sen. Harry J. McGuirk's underfunded and disorganized challenge to Hughes is likely to end with little tarnish to the incumbent's strong image. In the Republican primary, Pascal, the Anne Arundel County executive, has only token opposition from Baltimore surgeon and perennial candidate Ross Z. Pierpont.

A statewide poll released today by the Baltimore Sun showed Hughes leading McGuirk by nearly a 4-to-1 margin, with 62 percent of the respondents saying they would vote for the governor and 16 percent for his main challenger. Another 10 percent said they would vote for a third Democratic candidate, Ocean City Mayor Harry Kelley, and the rest were listed as undecided.

In an early test of the general election race, the poll showed Hughes leading Pascal 54 percent to 26 percent, making the race closer than previous polls had shown.

The Sun poll of 810 likely primary voters, interviewed between Aug. 30 and Sept. 1, revealed that among Democrats Hughes would have been extremely vulnerable to a challenge from the popular mayor of Baltimore, William Donald Schaefer, who chose not to make the statewide race. Schaefer, who has had a lukewarm relationship with Hughes and has yet to endorse him, outpaced Hughes in the Sun poll 45 percent to 33 percent.

Lou Panos, Hughes' press secretary, said the Hughes-Schaefer poll was of no significance. "It's easy to be popular when you're not running for a particular office," said Panos, who quickly added: "The mayor's a fine man and a fine Democrat."

The Senate primary contests have proved to be equally one-sided. Democratic incumbent Paul S. Sarbanes is expected to swamp seven minor opponents. And on the Republican side, Prince George's County Executive Lawrence J. Hogan, who got the backing of the state GOP leadership after some initial skirmishing, also faces only token opposition. He has spent most of the summer gearing up for a tough -- and potentially bitter -- campaign against Sarbanes.

In a Sarbanes-Hogan matchup in the general election, the Sun poll showed the incumbent Democrat leading Hogan 59 percent to 30 percent, with the rest undecided.

The Republican National Committee has targeted the Maryland Senate race and has said it will provide much- needed funds to Hogan. He also has been aided by television assaults on Sarbanes paid for by the National Conservative Political Action Committee (NCPAC).

Hundreds of other offices are being contested throughout Maryland in the quadrennial elections for all state and most local offices. In Prince George's and Montgomery counties, voters will nominate candidates for county executive, county council and the state legislature.

The lopsided quality of the gubernatorial campaign may be summed up by the actions of Hughes and Pascal during the last few weeks: Both men spent much of their time eyeing each other instead of their primary opponents and quietly honing themes for the seven-week general election campaign.

Hughes, who for the most part has avoided appearances with McGuirk and Kelley, has been filming television commercials for the November election and taking polls that focus on post-primary issues. He also has been trying out jabs that tie Pascal to the Reagan administration. Maryland was one of the few states Reagan lost in 1980 and his policies are considered unpopular among its mostly Democratic voters.

Pascal has downplayed his party affiliation throughout the campaign and has attempted to distance himself from the national administration. In preparation for the general election, Pascal strategists have been studying Hughes' 1978 campaign literature looking for unkept promises. And to overcome an image that Pascal is long on generalities and short on substance, they have been preparing position papers on prisons, economic development, senior citizens and drugs.

Pascal also has been offering encouragement to McGuirk, on some occassions calling McGuirk headquarters to discuss issues, hoping that a strong showing by the wily state senator would make a dent in the Hughes' perceived lead.

McGuirk's campaign has largely foundered since he announced his candidacy in March. Until last month, McGuirk all but ran his own campaign from the back seat of his car, lacking a manager, a scheduler or a press spokesman. His campaign people have complained all along that they could not"get a hook" in Hughes -- a problem also voiced by the Pascal campaign.

McGuirk's one apparent coup occurred in June when Lt. Gov. Samuel W. Bogley deserted Hughes after a stormy four-year relationship to become McGuirk's running mate. But even that advantage quickly fizzled when Bogley publicly criticized the campaign's lack of direction and wondered what McGuirk, a man known for always having some thing up his sleeve, was really after. Questions of a "hidden agenda" have plagued the McGuirk campaign throughout the primary.

In the last 10 days, McGuirk has scrambled to turn his failing campaign around, even as some radio announcers continue to mispronounce his name. (It rhymes with work.) Last week he released his first harsh attacks on Hughes--after failing to criticize the governor during the campaign's only televised debate. He also began airing what may be the best political commercial of the primary.

The TV spot, which centers on McGuirk's theme that the low- key Hughes has been a do-nothing governor, shows a clock ticking while a voice says, "Shhh . . . the governor is sleeping. He's been sleeping for four years." But because McGuirk had only $30,000 to spend in the last week, the commercial is running on only one Baltimore televison station-- and not in the Washington area, where McGuirk remains largely unknown.

The McGuirk commercial delighted the Pascal camp, which was forced to cancel its own television commercials because of fund shortages. When Pascal ran into McGuirk at a recent Democratic fundraiser, he told McGuirk, "I loved it. I wish my guys had thought of it."

Hughes also went on television in both Baltimore and Washington last week, more for the sake of post-primary momentum than for the primary itself. The governor's campaign had hoped to delay television time to conserve money for the general election.

Fundraising has been a problem for all the candidates, a factor attributed to the economy and a general political malaise. Hughes has raised the most, about $600,000, but that is considerably less than the $900,000 acting Gov. Blair Lee III raised for the primary in 1978. Pascal has only raised $333,000.

While issues have been discussed in the campaign, none has emerged as a centerpriece for any of the challengers, a factor that has worked to the benefit of the incumbent. "The best thing for us is if everyone goes to sleep," said Hughes campaign manager Joseph M. Coale III.

Hughes has also managed to do what any incumbent hopes to do -- play the role of statesman while avoiding scraps with his opponents. His most effective playing of the statesman role came early last month when, at the behest of labor, he called a special session of the Legislature to solve an unemployment benefits crisis. His successes were pronounced nightly in the media.

From the opening days of the campaign, the challengers have hop-scotched from issue to issue -- prisons, leadership, juvenile crime and economic development and unemployment -- trying to find one that would take hold. From the start McGuirk criticized Hughes, who struggled in his dealing with the legislature until this past winter, for lack of leadership. He could not make that into a major issue, however.

So he looked elsewhere, first attacking Hughes' handling of a new auto emissions inspection program as unnecessary, and then his handling of Bogley, whom Hughes dumped from his reelection ticket. Lately Mc Guirk has been trying to puncture Hughes' image as a "white knight," saying he plays politics as much as anyone.

Yet McGuirk stopped short of directly charging the governor with incompetence or mismanagement, saying instead that he could do better. In a televised debate last week in Baltimore, McGuirk failed to attack Hughes or draw any sharp distinctions between them, again leaving Hughes unscathed.