The results of Tuesday's elections in New Jersey and Virginia suggest decreased importance of party labels, declining influence of President Reagan in future political contests and a challenge to the notion that race divides southern voters, according to pollsters, political analysts and national party leaders interviewed yesterday.

The sweep in Virginia by a Democratic ticket that included a black and a woman, and the record win by a moderate Republican incumbent in New Jersey's gubernatorial election indicated that the nation is far less conservative than often portrayed, they said.

"What a difference a year makes," Democratic pollster Peter D. Hart said, comparing the Virginia results with the controversy last year surrounding Jesse L. Jackson's bid for the Democratic presidential nomination and the choice of Geraldine A. Ferraro as the party's vice presidential nominee. "It says, 'Look, if you've got candidates who are good, they can be elected on their own merits,' " Hart added.

"You need to put away all of your assumptions about who will win and who will lose according to the traditions of the state," media consultant Raymond D. Strother said. "You need to say, 'Will this guy win?' and then ask, 'Now, what party is he?' "

Looking toward next year's elections, when Democrats and Republicans will be vying for 34 seats and control of the Senate, Republican political strategist Edward J. Rollins said candidates must prepare to fend for themselves.

"Reagan, even if he is strong, is not going to hold the Senate purely on his strength . . . . What you're going to see in '86, if the economy holds up, is 34 individual races in which individual personalities are going to have more to do with realignment, dealignment or whatever."

Off-year elections are seldom considered harbingers of political trends, and in many respects this year's contests were no exception. Boosted by economic recovery, incumbents were the major victors, especially among the nation's mayors, most of whom are Democrats.

Gov. Thomas H. Kean (R) won a second term in New Jersey with 70 percent of the vote over Essex County Executive Peter Shapiro. Kean carried every group except Jewish voters, amassed a record 776,747-vote plurality and swept his party into control of the state Assembly.

In Virginia, former attorney general Gerald L. Baliles was elected to succeed fellow Democrat Charles S. Robb as governor, while state Sen. L. Douglas Wilder became Virginia's first black elected lieutenant governor and state Del. Mary Sue Terry its first female attorney general.

"In New Jersey, the Republican didn't run as a traditional Republican; in Virginia, the Democrat didn't run as a traditional Democrat," said consultant Lee Atwater, who was deputy director of Reagan's 1984 campaign. "We are not going through a realignment in politics, particularly in the South . . . . We're going through dealignment."

Democrats and Republicans characterized Wilder's victory as a breakthrough in the South. Noting, however, that he won by the narrowest margin on the Democratic ticket, they cautioned against expecting a sudden rush of statewide victories by southern blacks.

The candidacies of Wilder and Terry were less controversial because of the strength of Baliles, some said. "Racism would have been an unavoidable issue at the top of the ticket," Strother said. "It's a wonderful symbol for the South . . . but I don't take as much hope as most Democrats do . . . because it's the bottom of the ticket."

Still, Tom Houston, a political adviser to Los Angeles Mayor Tom Bradley, said he saw in Wilder's success encouraging signs for Bradley, who is expected to make another bid next year to become California's first black governor. He was narrowly defeated in 1982.

The Wilder campaign "must have struck a responsive chord in a conservative state, and I'm sure we'll be taking a look at how they did it," Houston said.

Looking at the results in Virginia and New Jersey, Republican National Committee political strategist William Greener said, "A big story from this is that black candidates, when perceived as being mainstream, are viable . . . and Republican candidates, when they have a genuine affinity, can gain support from black voters that nobody's seen in the past."