There was good news and bad news today for Sen. Edward M. Kennedy at the Mall of New Hampshire, the sprawling regional shopping center south of here.

The good news was that Kennedy had a 3.3 percent lead on President Carter in the cumulative voting of 3,221 shoppers, asked their preference in next Tuesday's New Hampshire presidential primary. The bad news was that Robert E. Lee is backing Carter -- not Kennedy.

Lee, a stocky 49-year-old employe of the Public Service Co. of New Hampshire, is the kind of voter whose support Kennedy needs to convert his lead in the totally unscientific shopping center straw vote into victory in the primary. Lee, a native of Massachusetts, moved here 14 years ago. Pointing to the $7,000 price tag on a Japanese-made sedan displayed in the mall, he said, "Inflation is out of control."

He thinks Carter has done "fairly well" in handling the Iranian hostage situation but regrets, "he's so involved with that, he doesn't tell you what he's going to do about anything else."

"I'd like to see him and Kennedy debate," Lee said."Seeing the two of them together would give me a better idea of what they'd do."

But despite his misgivings, which echoed the basic themes of Kennedy's campaign, Lee said he will probably vote for Carter. The Kennedy proposal for wage and price controls "would hurt the little guy more than it does the big shots," Lee said. "And besides, you never know with Kennedy. He turns things around so much, saying one thing and then the opposite, I don't know what to believe about him anymore."

That skepticism about Kennedy -- rather than any strong enthusiasm for Carter -- is what makes the president the favorite here next week and discourages the leaders of the dogged Kennedy campaign here.

The most recent evidence of Kennedy's uphill struggle came today in two new polls, one national, the other taken in New Hampshire.

A CBS-New York Times poll of 1,536 adults, taken Feb. 13-17, showed Carter leading Kennedy among Democrats, 58-23 percent. California Gov. Edmund G. (Jerry) Brown Jr. had 7 percent.

A poll of 1,320 voters taken Feb. 3-14 by the political science department of the University of New Hampshire showed Carter leading Kennedy, 47 to 29 percent. Brown had 6 percent, with 18 percent undecided.

The remarkable thing, according to Robert E. Craig, who conducted the poll with colleague David W. Moore, is that Carter polls higher than his approval rate. Only 35 percent in the sample approved Carter's handling of his job, and a massive 80 percent disapproved of his performance on the economy.

Still, Carter enjoyed an 18-point margin over Kennedy. Carter's strategists think that lead is exaggerated, and predict the "softness" of the Carter support will shave his margin below 10 points.

But even a single-digit victory over Kennedy in this New England state would be a major step toward renomination for the president. After the assumed Kennedy victory in Massachusetts on March 4, the senator faces a bleak run of southern primaries and a March 18 contest in Illinois, where his organization is weak and public disapproval of his candidacy is far stronger than it is here.

Thus, Kennedy and his New Hampshire organization have no choice but to try to close the gap in the remaining few days of this primary.

Their hope is sustained by the fact that, as a leading pro-Carter Democratic official remarked, "A lot of voters are really conflicted about this election. They're balancing Chappaquiddick against their feelings about Jack and Bobby, and they're weighing the patriotic fervor about the Persian Gulf against the price of fuel oil."

Private campaign polls show two particularly volatile voting groups. One segment is the liberal Democrats in university cities like Durham and Hanover, where Kennedy must roll up a big margin to win. But the senator is being forced to share the antinuclear, antiregistration, anti-Carter vote with Brown, who comes back here Wednesday for six solid days of campaigning. Today's poll showed Kennedy trailing Carter by 12 points among self-described liberal Democrats.

The larger swing vote consists of middle-aged blue collar Democrats, many fairly conservative ethnic Catholics. Among them, private pollsters report, sentimental and economic issue support for Kennedy often runs up against disapproval of his stands on gun control and abortion and his behavior in the Chappaquiddick incident.

Robert E. Lee said Chappaquiddick did not enter into his thinking because "all of them have some skeletons in their closet." But a man of about the same age, who declined to give his name because he works for the county corrections department, said he would support Carter because "I can't believe anythng Kennedy says. Chappaquiddick showed he's completely two-faced."