Usually, the differences between Republican and Democratic voters in the primaries are socioeconomic. Republicans, it can safely be said, are generally richer and better educated.

But that was not the big difference in the New Hampshire primary. The parties split principally along gender lines: men flocked to the Republican primary, while women chose to vote in the Democratic contest. A gender gap that widened in the 1980’s and 1990’s may be more pronounced than ever.

Women accounted for 62 percent of the Democratic electorate in New Hampshire, compared with 54 percent in 1992 and 52 percent in 1988. In the Republican primary, men made up 57 percent of the Republican vote, comparable to the profile in 1996, when Bob Dole and Pat Buchanan were vying for the nomination. By contrast, men made up only 51 percent of the G.O.P. electorate in 1988, and they voted in larger numbers this year.

Like Latin nouns, many of our recent elections have been identified as male or female. Remember, 1992 was the “year of the woman,” while in 1994 we had “angry white men.” Two years later, “soccer moms” was the catch phrase. They morphed into “waitress moms” by 1998. But the size of the gender imbalance in New Hampshire was a shock, and it may hold true throughout the campaign.

First, men tend to have a big problem with Al Gore. In six national Pew Research Center polls taken in the last nine months, support for Mr. Gore, when pitted against George W. Bush, never rose above 40 percent among men. Mr. Gore’s leadership ability, not the issues, is the problem, say the respondents who do not back him. And in considering qualities they want in a president, men did not rate Mr. Gore’s strong points — compassion, willingness to compromise, experience in Washington and loyalty — as highly as women did.

Indeed, when our polls in October asked respondents to come up with a spontaneous one-word description of the vice president, more men than women poked fun at Mr. Gore (24 percent to 15 percent), using words like “stiff” and “boring.”

Among women, Mr. Gore’s support has wavered — from 40 percent to 50 percent in Pew’s national polls. Generally, however, women have a more positive impression of Mr. Gore personally and, according to a Gallup poll, more women than men (55 percent to 47 percent) say that Mr. Gore shares their values.

Moreover, women tend to be more loyal to the Clinton administration. A Pew survey in August of nearly 3,000 registered voters nationwide found that 57 percent of male voters wanted the next president to offer policies and programs that are different from those of the Clinton administration. But women are evenly divided: 46 percent wanted the next president to continue Mr. Clinton’s policies; 45 percent wanted change.

Exit polls in New Hampshire suggest that President Clinton was a clear positive for Al Gore among Democratic women. They assured Mr. Gore’s victory by giving him a 53 percent to 47 percent margin over Bill Bradley, while the male vote split evenly (49 percent for Mr. Gore; 50 percent for Mr. Bradley), according to the Voter News Service exit poll.

Mr. Gore won a narrow victory, polls showed, because female voters considered issues to be more important than personality (55 percent to 41 percent). Democratic men, especially those who backed Mr. Bradley, cared more about personal qualities than issues (52 percent to 46 percent).

On the Republican side, John McCain won his sweeping victory in a male-dominated primary where most voters said personality was more important than ideology. The Republican women who voted favored Mr. McCain over Mr. Bush by the same percentage as the men did. But should Mr. McCain win the nomination, the gender gap could widen in the general election.

That’s because men are generally more drawn to voting for change than women, and they find outsiders more appealing. Both themes are clearly central to the McCain message.

A Newsweek poll last weekend tested all the possible combinations for next November and found that a McCain-Gore matchup had the widest gender gap. Women strongly backed the vice president; men gave equally strong support to Senator McCain.

But whoever the candidates are in the fall, if the New Hampshire primary and the early polls are any indication, the winner may owe his victory to a swing group dominated either by men or women.