There is an unlikely new hero on campus here this fall. A lot of students describe him in pop culture terms as "larger than life" and a representative of "the kind of psychology the Pepsi generation lives on."

His name is Ronald Reagan.

He is 73 years old, a conservative and the very antithesis of the counterculture that dominated campuses a dozen years ago.

This seems to suit a majority of students at Ohio State University just fine, although the generally positive feelings many expressed about President Reagan mask other attitudes that may give Democrats hope of capturing a generation that both parties say is up for grabs.

"Ronald Reagan presents a very positive image. He looks like a man who knows what he's doing. He is the perfect media president," said Todd Shafer, president of the undergraduate student government. "We finally have a hero, almost a role model."

Democratic presidential nominee Walter F. Mondale provokes little such enthusiasm, even among his student supporters. "He is wishy-washy. He's not strong," said Mike Casey, a senior from Cleveland. "I'll vote for him because he's the lesser of two evils."

"Reagan would carry this campus pretty handily, perhaps by a 3-to-1 margin," said political science professor Herb Asher, a liberal Democrat, who describes it as a victory of style over substance. "Kids live by television and Reagan is the preeminent television performer. They can take him in 30-second spots."

Samples of college students from national public opinion polls generally are too small to tell if Reagan is as popular on other campuses as at Ohio State, never a hotbed of radicalism. But they indicate that Reagan is at least holding his own among college students, a liberal group until recent years, and he is running exceptionally strong among all voters under 25.

A recent Republican poll of Ohio, for example, showed Reagan is supported by 60 percent of voters age 18 to 24.

The latest Washington Post-ABC News poll finds Reagan leading Mondale 58 to 38 percent among voters in this age group who have at least some college education. Reagan runs best in the South among this group, while he and Mondale are about even among them in the Midwest.

Recent polls conducted for the Republican Party and the George Gallup organization also show young Americans identifying with the GOP in larger numbers than at any time since the 1960s, leading some to speculate about a party realignment favoring the Republicans.

Extensive interviews here indicate such hopes are premature, and feelings about Reagan are much more complex than they appear on the surface. These interviews provide a glimpse at a deeply polarized generation, and offer serious warnings about the future for Republicans and Democrats.

Almost everyone agrees that conservatism has become fashionable on this campus.

"It's not like they told me college would be, all those radicals hanging out. I don't know where they are," complained Jonathan Kandell, who helped organize Students for Peace and Disarmament, which he describes as one of only two "progressive" groups on campus. "It's hard not being a conservative. You get ridiculed and called a radical communist."

Every day Kandell's group sets up voter registration tables on campus. "To be perfectly honest, I think many of the people we're registering will vote for Reagan," he said. "We're registering a lot of Republicans which may be a disservice to the causes we believe in."

Rich Cardwell, a senior from Ironton, attributes the philosophical shift to economic uncertainty in recent years. "This generation is very conservative because admittedly we are very selfish," he said. "We are very career-minded. We grew up in a very tough economic time. The job market was very tight. It required all of our energy just to make it, to get ahead. We didn't have time to go out and support every cause."

Challenging the establishment has taken a back seat among many of 25 students interviewed. "I like Reagan's attitudes about big business because big business is what makes America go," said Jim Mealler, whose long hair and blue jeans might have marked him a "hippy" little more than decade ago.

The good news for Republicans is that these students like Reagan. The bad news for Republicans is that many Reagan supporters disagree with the New Right social agenda adopted by the party, especially its opposition to legalized abortion.

"If I don't vote for Reagan, it won't be because of him but the party platform. I've very concerned about the rightward drift of the party," student leader Shafer said in words echoed by other students. "I think it is the right of the mother to make a decision on abortion. I believe there should not be prayer in schools and I've very opposed to the religious emphasis in the campaign. Jerry Falwell seems to be against everything under the sun except God-fearing, white males."

Equally important is what might be called the Carter factor. The typical college junior was born in 1964 and has vivid memories of only one Democratic president -- Jimmy Carter. It is hard to overstate the disillusionment with him.

"His presidency was a fiasco. He didn't have the backbone that was needed to lead the country," said Patrick Piccininni, a sophomore business major. "Iran was a prime example. It wouldn't have been tried under Reagan."

"I remember growing up and wanting to be proud to be an American. Under Carter, I was tired of getting kicked around all the time," said Bryan J. Herd, a political science major. "Reagan has it over him hands down."

The good news for Democrats is that the party retains a strong corps of support. Reagan has polarized the campus dramatically, creating a substantial anti-Reagan vote. There appears to be no middle ground as far as the president is concerned.

Asked to describe Reagan, his supporters use words such as "patriot," "leader," "strength" and "great communicator." His detractors use words such as "fascist," "friend of the rich," "incompetent," "hawk," "phony," "actor," and "PR man."

"I think Ronald Reagan is extremely dangerous. He has a habit of bringing people into government who are blatant sexists, corrupt and everything else. He is completely for major corporations and against women," said Chelle Mathews, a junior computer-science major.

Idealism remains strong among many students. Many express a deep skepticism of Reagan's campaign style and his not negotiating nuclear arms-control measures.

"It would be easy to vote for Reagan if all you did was look at his commericals," said Janice McCoy, a senior from Dayton. "I think he'd be a great grandfather, but I don't think I want him again as my president. The deficit scares me. He's just blown over the issues. Walter Mondale has enough guts to stand up and say we've got to raise taxes. I'm not against paying a little more if it might help in the future."

The bad news for Democrats is that they have failed to capitalize on these feelings or mobilize support from students. The Young Democrats Club is not a force on campus, and students who have called party headquarters to volunteer to help the Mondale campaign have not received calls in return. By contrast, college Republicans are well organized, and have an active Reagan-Bush effort.

There also is little affection for party standard-bearer Mondale, who many middle-class students view as the captive of unpopular labor bosses. Sen. Gary Hart (D-Colo.), who won the Ohio presidential primary, Sen. John Glenn (D-Ohio) and Jesse L. Jackson each created more excitement on campus than the former vice president.

Mondale supporters describe Mondale as "bland," "monotone," "wimpy," "Hubert Humphrey-like," "struggling," and "concerned."

"I think I'll vote for him, not because I'm excited about him, but because I don't like Reagan," McCoy said.

Even more important, Republicans, at least those among students interviewed here, have captured the "future issue." Reagan is regarded by his supporters as the candidate of opportunity.

"When it gets down to it, Mr. Reagan has made the job market better. If Mr. Mondale gets into office, he is going to take money from my paycheck and put it into someone else's pocket," said Hugh Mills, a senior from Cleveland.

"People our age want to make a good living for themselves . . . . I think Reagan offers me opportunity."