The Democrats, confident and organized, swept into Montgomery County almost before sunrise yesterday, led by Gov. Harry Hughes and with their dozen-stop, 15-hour two-county day laid out before them.

Meanwhile, Republican Robert A. Pascal, accompanied by Lt. Gov. Samuel W. Bogley, in self-imposed exile from the Democratic party, was quietly campaigning in Prince George's County, hoping Bogley might somehow become a zero-hour savior in his home county.

Hughes, as he has often done on recent campaign swings, was part of a coterie of incumbent Democrats, including Sen. Paul S. Sarbanes, state attorney general Stephen H. Sachs and comptroller Louis L. Goldstein.

That quartet, together enough lately to form their own musical group, played their usual numbers to Montgomery and Prince George's county audiences: Stomp on Reagonomics; Rip the National Republicans, and their favorite, Ignore the Opposition. As usual, their gigs were carefully arranged, beginning at 6:45 a.m. at a subway stop and ending at the University of Maryland late last night.

Pascal, frustrated by constant questions about the way his campaign has been run, also began at a Metro stop, 75 minutes later than the Democrats, and plowed through the county with Bogley. In sharp contrast to the Democrats, Pascal and Bogley campaigned with no ticket mates and just one aide, pausing only long enough for a fast-food hamburger for lunch.

The challenger was without one of his campaign mainstays. His wife Nancy, feeling weak for days, yielded to Pascal's requests that she go home and rest.

"I feel terrible doing this," she said. "It makes me feel like I'm giving up."

Her husband insists he has not given up, in spite of polls that show him trailing Hughes by a large margin. Nevertheless, he was not the feisty, enthusiastic candidate of the summer. Like most of those around him, he was quiet, almost low-key, at one point turning to a reporter to say, "You know, the sun's still going to come up and the birds are still going to shine on Nov. 3."

Bogley's presence added to the morbid atmosphere of the day. The lieutenant governor was dropped by Hughes in June after nearly four years of disagreements. He attempted to retain his job by becoming the running mate of Hughes' primary opponent, State Sen. Harry J. McGuirk, and McGuirk's 3-l defeat, Bogley has deserted the Democrats to work for Pascal and GOP Senate nominee Lawrence J. Hogan.

Yesterday, at the courthouse and county administration building in Upper Marlboro, Bogley passed out Pascal literature in some instances to secretaries who had worked for him when he was a member of the County Council there.

"I've got to do what I can for my man," Bogley said of his role in yesterday's tour, which was directed by Lawrence Hogan Jr., son of the Senate nominee. "I'll help Bob as much as I can."

In contrast to the low-key Pascal push, the Democrats were upbeat, joking with each other and the voters whose hands they pressed.

In the modern Montgomery County Court House in Rockville, the Hughes foursome, accompanied by three Democratic County Council members, County Executive Charles Gilchrist, Rep. Michael Barnes and several state legislators, accosted dozens of voters eating at the cafeteria, interrupting some in mid-bite. Sachs quipped to one group, agog at the commotion caused by politicians and television cameras: "You're getting several politicians for the price of one. Pause What's the price of one, you might ask."

At Leisure World, an "adult community" near Olney, things got more serious, as Sarbanes called for Maryland's heavily Democratic electorate to "send a message that voters do not approve of what the Reagan Republican administration is doing to this country."