By the spring of 1967, students at the University of Maryland had learned to dread Journalism 191, a course called "Law of the Press."

The teacher was a hard-nosed attorney, public relations executive and former FBI agent named Lawrence J. Hogan. He was notorious for being tough on grades, requiring attendance and, worst of all, holding class three times a week at 8 a.m.

"I had to take the course to graduate," remembers Ira Allen, former managing editor of the campus newspaper, The Diamondback. "I waited an extra semester to get my degree, just so I wouldn't have to take the course from him."

This is the sort of legend that delights Larry Hogan now, as the energetic 54-year-old Prince George's county executive makes a bid to become a Republican U.S. senator from Maryland. The image of toughness and discipline-which at times has worked against him -- is central to his campaign against incumbent Democrat Sen. Paul S. Sarbanes, whom Hogan has denounced as a "do-nothing senator" and "an inept wimp" who has failed to sponsor any major legislation since getting elected in 1976.

"Maryland needs a more aggressive and more faithful U.S. senator," Hogan says on campaign stops across the state. "And, heaven help me, if nothing else, I am aggressive."

This aggressive persona has been Hogan's trademark in his varied career: as a scrappy Irish-Catholic kid from a blue-collar family in East Boston who worked his way through Georgetown Law School, as agent Hogan in the FBI, as founder of his own business, a public relations firm called Larry Hogan Associates, as a conservative three-term congressman from Prince George's County from 1969-75, as vice president of the Associated Builders and Contractors and now as a controversial Republican executive in a Democratic stronghold.

"The people of Maryland need a fighter in their corner . . . . Larry Hogan not only works for the people, he fights for them, and wins!" is Hogan's campaign slogan. He admires former president Harry Truman, he says, "because he was gutsy." He describes himself as a "tough taskmaster," prides himself on his outspokeness and on "taking tough stands, even if they are unpopular."

For Hogan, "the fight" has been a key to moving up in life at every step.

"There are a number of difficult things that he wanted to do, and he went after them and did them," says his longtime friend, Prince George's businessman Raymond G. LaPlaca. "I mean, he wasn't exactly your typical FBI agent. He's short, he's stocky, he's not exactly Efrem Zimbalist or anything. But he wanted it and he did it. It takes a certain kind of inner drive."

Now, however, with one week remaining before the Nov. 2 election, Hogan's fight, in part, comes down to one against notoriety, against the very image that has evolved during his political career. In places that he is well known, such as the Washington suburbs, recent newspaper polls show almost even numbers of voters who like and dislike him, a reflection of his visceral reactions and his penchant for controversy.

"Our pollster Houston-based Lance Tarrance says he has never seen such a dichotomy," says Hogan's son, Lawrence Hogan Jr. "Some people dislike him because he is outspoken. He doesn't enjoy the image. He sees himself as straightforward. He may say things people don't like. But at least they know where he stands."

This year Senate candidate Hogan has had to endure the painful discovery that there are long-term liabilities in using political crises to draw attention to one's self. Even among his fellow party members, his history -- his call for President Nixon's impeachment during Watergate in 1974, his son's candidacy for Congress last year, his reaction to a public employes' strike in the county in 1980 -- has been an obstacle in this year's campaign, slowing contributions from conservative political action committees around the country that are essential to his race. It was not until last summer that, after months of public feuding, the state's GOP leadership united behind him. The divided opinion prevented him early on from capitalizing politically on the appealing parts of his personality, the self-effacing, witty and charming sides that contrast sharply with his more sober opponent.

"He has a reputation, deservedly so, for being pushy," says one leading Maryland Republican who supports Hogan's candidacy. "In a curious and enigmatic way he has developed a reputation as aggressive, pushy, and as a loner. His problems have arisen from his manner and his ambition, not from his ideology. Sometimes he seems blind to the damage he'll do to himself."

Hogan's bid for the U.S. Senate seat began more than a year ago. Although he says his talents are more suited to being governor -- he believes he is a better administrator than legislator -- he decided to run for the Senate instead because the odds of a Republican victory seemed greater.

Hogan's aides say he could have been reelected to a second four-year term as county executive if he had wanted it. Many Maryland political observers disagree, and they are supported by polls that show Hogan trailing Sarbanes in Prince George's County. They believe he was prompted to seek state-wide office because he had lost his base of support in the county.

His toughest obstacle goes beyond the county line: He is trying to win state-wide office as a Republican of the conservative stripe in Maryland, one of six states where voters rejected President Reagan in 1980.

Hogan has pinned his hopes of victory on his record as a congressman (he served on the House Judiciary Committee and was author of the D.C. Crime Bill), his tireless and masterful ability as a campaigner, on what he still believes is Sarbanes' vulnerability, and on appealing state-wide to Democrats and blue-collar voters, the kind of people who had helped elect him in Prince George's County.

With his background in public relations -- his wife, Ilona, calls him "the consummate salesman"--he set about marketing himself and his beliefs as political products, just as he has done for years in public life. He has toured the state for months, always dressed in a pin-striped suit, always quick with a handshake and a pat on the back, always full of the easy-going banter that is often concealed by his more aggressive side.

To convert traditional Democratic voters from blue-collar and ethnic areas, Hogan, a stalwart supporter of Reagan's economic program, has presented himself as an Irish-Catholic candidate (his campaign colors are shamrock green and white) from a working class family who is "fighting for the little man."

To blacks, who vote overwhelmingly for Democrats, the former champion of the antibusing movement in Maryland touts his appointment of the first black deputy police chief and black director of personnel in Prince George's, says he was the first Maryland congressman to employ blacks as staffers and that he voted for federal fair housing laws; points out that he lives in a predominantly black neighborhood, and says that boxing champion Sugar Ray Leonard has been a friend since Leonard's boyhood.

To Republicans, who make up one-fourth of the state's electorate, Hogan has stressed his credentials as a solid and loyal conservative who supports Reagan on the economy, national defense, abortion and school prayer. (He differs with Reagan on a few issues, such as federal reductions in force). "Sarbanes is an excessive liberal," he says. "Maryland voters have never had a clearer choice than in this election."

If Hogan's campaign strategy has stumbled, it is because, in some instances, his gift for seizing the political limelight, so well documented during his three terms in Congress, has become a liability.

"I don't think anyone is going to deny that Larry has burned some bridges over the years," says one Republican staffer in Congress. "He practices aggressive politics. Some call it confrontational politics."

Today, some staunch conservatives still resent Hogan's call -- the first by a Republican congressman -- for Nixon's impeachment, believing it was a traitor's act against the party. (Hogan blames the announcement for his loss to Louise Gore in the GOP gubernatorial primary that year). Some key Maryland Republicans still talk about his "heavy-handed" and unsuccessful maneuvering to become chairman of the state delegation -- which included better-known politicians such as Sen. Charles McC. Mathias, Rep. Marjorie S. Holt and Rep. Robert Bauman -- to the Republican National Convention in 1980. (Hogan tried to enlist support by delivering strawberries and free newspapers to the hotel rooms of party members who had convened in Ocean City).

But nowhere has the wrath fallen upon him more heavily than in Prince George's county, where his four-year tenure has been marred by highly-publicized clashes with the police, teachers, and public employes unions.

"His political instincts are always to create a dichotomy on issues," says his long-time Democratic rival, Parris Glendening, a Prince George's county councilman and candidate for executive who is favored to win the election. "At an early stage the polarization is effective, because it produces devout loyalists. But another group becomes intensely hostile. Sometimes his political instincts are so good. And sometimes they are so bad."

The Fraternal Order of Police supported Hogan in 1978, only to plant "Hogan is guilty" signs in the police headquarters lawn after contract disputes and disagreements over Hogan's choice for a new county police chief. Laney Hester, former president of the FOP, now says: "He's a little Napoleon. He has a Waterloo everyday."

Lawrence Joseph Hogan was born in East Boston but moved to Washington as a boy. He went to Gonzaga High School, where he received a Jesuit education and formed some of the conservative opinions that have stuck with him today. But his background does not completely explain his ideology.

Hogan's father was a victim of the Depression who lost his job and demanded that his son learn the value of work. His father, who died in 1953, was a loyal union man and a solid Democrat.

"Do you think Dad would have voted for me?" Hogan asked his mother after being elected to Congress.

"He might have," she replied.

Hogan joined the FBI in 1948 and became interested in politics 10 years later when he was asked to write a summary on Democratic presidential hopeful John F. Kennedy. He says he was the first volunteer in Kennedy's Maryland campaign, but explains, "I started listening to his speeches and didn't like what I was hearing, so I switched parties and voted for Nixon."

Agent Hogan left the FBI (his favorite case was solving a child abduction crime in North Carolina) in 1959, began his public relations firm, got involved in county politics and became a lecturer at the University of Maryland. He went to the Republican National Convention in 1964 and two years later made his first bid for office. Hogan recruited students in his classes to help with his grass-roots campaign for Congress.

Able to raise only $11,000 for the race, he lost to incumbent Rep. Hervey G. Machen by four percentage points (he frequently reminds potential contributors that with a few more dollars he might have been able to win), but he attracted publicity by tying himself to a federal investigation of corruption that resulted in the conviction of Democratic County Commissioner Jesse S. Baggett. Two years later the publicity paid off and he went to Capitol Hill.

In the 14 years since he won his first election, Hogan has developed a small cadre of loyal supporters. His closest friends worked on his first campaign and are still with him today, and have learned to live with the controversies that have enveloped him.

"Sometimes it amazes us just what he will say to the press," says one top aide. "It makes you want to pull your hair out sometimes. But that's the way he is. He wears his emotions on his sleeve."

Hogan's wife, Ilona, his former student and press secretary who is now an attorney, says he has mellowed some in the past eight years, largely the result of starting a second family and having four young children. "He's moderated a little bit," she says. "He's made it. He doesn't need to climb any more."

For weeks now, Hogan's campaign aides have struggled over whether to temper the better-known aggressive image in television advertisements, whether to reveal to voters the Larry Hogan who laughs at himself and teases his aides and the press, the down-home guy who can't resist a piece of home-made pie, the father and husband who loves writing poetry, reading novels and spending time with his children.

"The toughest question of the campaign is whether to show the real softer side of the guy," says media adviser Jay Bryant. "People had heard a lot of negatives about Larry, and we want to suggest that maybe he isn't as bad as suggested by some of his critics. But at the same time we are trying to show what a softy, what a nudnik, Sarbanes is. You try your darnedest to exploit what is true of Larry that also contrasts with Sarbanes. And Larry is aggresive and action-oriented."