Robert A. Pascal, Republican candidate for Maryland governor, walked into the supermarket followed closely by his six-person campaign entourage. He had already toured most of the stores in the Loehmann's Plaza Shopping Center in Rockville and hands available for shaking had been few.

Now, entering the Safeway, Pascal found himself staring at rows and rows of food. But no people. Food can't vote. Frustrated, Pascal shook his head.

"Where," he said spreading his arms, "are all the people in Montgomery County?"

For a moment, he stood still. His wife, Nancy, finally broke the embarrassed silence.

"Give me $20," she said. "I can do some shopping."

Pascal sighed. His first major campaign day in Montgomery County was turning into a long one. As Anne Arundel County executive the last eight years, Pascal, 47, is known to the people there and in the Baltimore area. But a poll taken for him in May showed his name recognition in this area hovering at about 10 percent. As Pascal often says, "If people don't know you, they can't vote for you."

Yesterday was the first of a semi-blitz in the Washington suburbs. Pascal is keenly aware of how important the area is going to be to him if he is to upset incumbent Democrat Harry Hughes this fall. He plans to come back at least once a week prior to elections.

"It's very simple," he said between campaign stops. "If we do well in Montgomery and Prince George's counties, we're going to win. But it's going to take a lot of hard work."

Pascal learned a good deal yesterday about just how hard that work is going to be. In the morning, stopping by two senior citizen homes, some people greeted him warmly. But when he ventured to the shopping center, the going got tougher.

Most of the people he encountered had obviously never heard of him. Those who stopped to talk asked questions like:

"What are you running for?" and "Where are you from?"

Others didn't bother to ask. One woman in the supermarket took a Pascal brochure, turned to her son to ask what kind of lemonade he wanted to buy, then dropped the brochure into the lemonade freezer.

As Pascal approached another man, hand extended, the man waved him off. "Leave me alone," he said. "I'm a Democrat."

Pascal shrugged, but his wife was shocked.

"I can't believe this," she said. "Some of the people down here are so hostile. It's not like this back home at all."

That may be the lesson Pascal learned on a rainy day in August. He is not running for county office now, not running in a race where everyone knows him or in a county where Democrats frequently cross party lines.

The hostility he encountered seemed to surprise him. "This was the wrong place to come," he said. "There just aren't any people here and some of the ones that are here aren't that interested in talking to me.

"We're going to have to go on the tube, we're going to have to go on radio, we're going to have to talk to as many people as possible and I've got to debate Harry. Heck, if I have to, I'll even debate (Hughes press spokesman) Lou Panos. He's the one always answering questions anyway."

Many of the questions Pascal answered yesterday were about President Reagan. At the two senior centers, Reagan's name was somewhat akin to mud and Pascal was dragged into it.

"I've got only one problem with you and that's Ronald Reagan," said Thelma Kasza as Pascal worked his way through a meeting room. "He's a Republican and so are you."

One man looked up from an intense game of stud-poker and said, "but you're a Republican?"

"Give him a break," said the dealer slapping a card down, "Abe Lincoln was Republican too."

To the many people who asked him where he stood on Reagan, Pascal repeated his stock answer: "When the president does something that helps the people of Maryland, I will praise him. When he does something that hurts them, I will criticize him." One of the seniors wanted to know how Pascal felt about the constitutional amendment calling for a balanced budget. Pascal hedged. "I don't know enough of the specifics," he said. "The theory is a good one but I need to know more about just what kind of cuts are going to have to be made if we do it."

The day was not without positive moments. As Pascal prepared to leave one of the senior citizen centers Edith Papace, came up and shook his hand warmly. "You're the first politician I've met in a long time who seems like a human being," she said. "I'm voting for you."

Pascal beamed. "We need more of that," he said.