As Democrats race toward the Illinois primary, the election is more and more seen as a contest between Walter Mondale and Gary Hart. But there are other ways to characterize the struggle between these two men.
Election experts say it's also a tug of war between traditional Democrats (for Mondale) and independents (for Hart).
* It's low-income voters (for Mondale) against upper-income voters (for Hart).
* It's older voters (Mondale) against younger voters (Hart).
* It's less-educated voters (Mondale) vs. college graduates (Hart).
Thanks to high-speed computers and thousands of voter interviews, analysts can tell us more today about voter trends than anyone dreamed of a few years ago.
Such detail offers us valuable guides about what might happen in the next big contest - the Illinois primary on March 20.
These studies tell us, for example, that George McGovern's withdrawal from the race should help Senator Hart more than Mr. Mondale.
The profile of a typical McGovern voter (young, well-educated, high-income, white-collar, politically liberal) is exactly where Hart is drawing some of his most solid support.
They also tell us that Jesse Jackson's powerful showing among black voters is making it a lot harder for Mondale to slow Hart's momentum. Hart gets few black votes. So the longer Mr. Jackson stays in the race, the better it is for the senator from Colorado.
That brings us to Illinois.
The Prairie State should be strong Mondale country. Over 40 percent of its Democratic voters are blue-collar union members. About 30 percent are black. Illinois has struggled with high unemployment and poverty - issues where Mondale is considered strong.
Yet the contest with Hart is seen as a tossup.
Part of the reason is that Hart has attracted large numbers of voters, many casting a ballot for the first time, who consider themselves only ''weak'' Democrats. He also gets the largest share of independents.
The Hart style, in fact, is ideal in an age when party loyalties have waned. Today, a candidate like Hart who shows his independence of party bosses, looks good on TV, and can get across his message in just a few words (''new ideas,'' ''a new generation of leadership'') can be a real political force.
Mondale, now faced with the Hart phenomenon, will do his best to solidify his traditional Democratic support in Illinois. But just as important, he must reach out to those voters who don't walk the party line so closely.
Here's what the computer studies tell us are the strengths and weaknesses of each candidate as the primary in Illinois, the biggest industrial state yet to vote, draws near. Most of the data come from thousands of interviews with actual voters this week in Florida, Georgia, Alabama, Rhode Island, and Massachusetts. The data were compiled by two television networks, ABC and NBC, and provided to the Monitor.
The Hart-Mondale contest, in part, turns on personal characteristics. Both Hart and Mondale have certain advantages, according to the voters.
Mondale, for example, is praised for his experience. He also would probably do better in a crisis, the voters say. And most voters, when comparing Hart and Mondale, say Mondale would probably provide somewhat stronger leadership.
Hart, however, has other perceived strengths which often outweigh those for Mondale.
By and large, the most important thing the voters are looking for this year is a candidate who will ''bring needed change.''
Most Democrats, by a wide margin, think Hart would be far more likely to bring fresh ideas and programs into the federal government.
Hart also is seen as more independent, and somewhat more likely to ''get things done,'' once he got to the White House.
Each man, therefore, has his own personal strengths. In brief, it comes down to a choice between experience (Mondale) and change (Hart) for most voters.
There is no single issue that dominates this campaign. Voters mention foreign affairs, poverty, the federal deficit, red tape, threat of war, taxes, and others.
Mondale and Hart again each have their strengths. In brief, Hart is usually seen a little better on the economy, Mondale a little better on foreign affairs.
There are exceptions to that general conclusion, however. Hart, for example, gets higher marks on the nuclear-freeze issue, while Mondale is judged to be more interested in helping the needy.
One of Hart's great advantages in this campaign has been his appeal across the political spectrum. In Massachusetts, for example, Hart got the votes of liberals (39 percent), moderates (45 percent), and conservatives (46 percent).
Hart managed this wide support even though he's generally regarded as a liberal senator. One reason may be that the senator still is not very well known. But he has also been careful not to offend any major ideological bloc.
By contrast, Mondale's views as a liberal are widely understood. And you can see the results in the voter surveys. He's strong, as might be expected, with liberals. But among conservatives, he's usually much weaker.
Here's are some other highlights of the studies:
* Religion doesn't seem to be influencing the choice between Hart and Mondale. Voters who think abortion is a key issue split evenly between the two men.
* Men and women are voting almost identically. Hart made a special appeal to women voters earlier in the campaign, but men seem to like him just as much.
* Age is a real factor among voters. Mondale is at his worst with voters under 40. Hart drops off with voters over 60. But as the contest continues, Hart is gaining strength with older voters.
* Education is one of the great dividers. Among those with less than a high school education, Mondale runs away with the race. Hart's at his best with people who attended college, though his supports drops slightly with those who did graduate studies.
* Race also is a key indicator. Mondale gets several times as many black votes as Hart.
* Party loyalty is another determinant. In Florida, for example, Hart won by a wide margin on Super Tuesday. But among those who consider themselves ''strong'' Democrats, Mondale came out on top. It was independents and self-styled ''weak'' Democrats who gave Hart his edge.
* Occupations also are important. Hart does well with white-collar workers, professionals, and managers. Mondale is at his best with blue-collar workers, housewives, and retired people.
Finally, John Glenn's future plans may have a major impact on this race. He has called a press conference for today to reveal his plans.
Already, Senator Glenn has closed his campaign offices in New York, Alaska, and Kansas. He has fallen $2.5 million into debt.
If Senator Glenn steps out, it will be another boost for Hart. Glenn's support comes heavily from upper- and middle-income, well-educated, independent-minded people - just the kind who seem to like Hart's style.