With just over three weeks remaining before the Nov. 2 election, Maryland's Democratic incumbents, Gov. Harry Hughes and Sen. Paul S. Sarbanes, hold commanding leads over their Republican challengers, according to separate polls released today by two Baltimore newspapers.

The polls are particularly bad news for GOP gubernatorial candidate Robert A. Pascal, who appears to be losing ground in his bid to unseat Hughes. Both polls show Hughes with 60 percent of the vote and more than a 2-to-1 edge over Pascal.

Every category of voter in the Baltimore Sun poll preferred Hughes over Pascal, including Republicans, supporters of President Reagan and residents of Anne Arundel County, where Pascal is the county executive. Hughes picked up six points since the Sun's earlier poll a month ago.

The Republican's biggest problem seems to be that voters don't know who he is. Roughly 75 percent of those polled by the Sun said they knew only "a little" or "almost nothing" about Pascal, who has curtailed his crucial media campaign because of lack of money. Both polls were conducted before Friday night's televised debate between the gubernatorial rivals.

The most striking poll result shows Sarbanes, the target of a $625,000 media campaign sponsored by the right-wing National Conservative Political Action Committee, with surprising support among voters who describe themselves as "conservative."

In a Baltimore News-American-WBAL-TV poll of 775 likely voters, Sarbanes and Republican challenger Lawrence J. Hogan both won 42 percent of the self-described "conservative" vote. Only 5 percent of the respondents said their preference for Hogan or Sarbanes was determined by the NCPAC ads, which say that Sarbanes is "too liberal" for Maryland.

The News-American -- WBAL poll, conducted by Potomac Survey Research Inc. of Bethesda between Oct. 1 and 4, shows Sarbanes leading Hogan among likely voters by 54 to 33 percent, with only 13 percent undecided. Hughes beat Pascal by a 60-to-27 margin, compared to 60 to 25 in the Sun poll.

The Sun poll of 823 likely voters, conducted by Hollander, Cohen and Associates between Sept. 28 and Oct. 1, shows Sarbanes leading Hogan 59 percent to 25 percent, with 15 percent undecided. The News-American-WBAL poll shows Sarbanes beating Hogan in Prince George's County, where Hogan is county executive, by a 51-to-37 margin.

The only sign of hope for Hogan appears to be in the blue-collar areas of Baltimore and its suburbs, where the News-American poll found he has made some inroads despite the huge preponderance of Democrats.

Pascal, according to the Sun poll, lost the lead he held in Anne Arundel County in the earlier poll, but made dramatic gains in Baltimore County, where he is reasonably well known. Hughes' 42-to-28 lead a month ago in Baltimore County had narrowed to 45 to 42.