These are already long, emotionally draining days for Jesse Helms. His conflicting roles as a senator, candidate and spokesman for the conservative movement have left him tired and worn.

He is deeply disturbed by what he calls "the most traumatic event of my life," the recent shooting down of Korean Air Lines Flight 007, which he had been scheduled to take.

The normally courtly Republican has become testy with reporters, and he complains that the long knives of the press are out for him in his reelection race next year against North Carolina's Democratic governor, James B. Hunt Jr.

The latest public opinion poll here showed him trailing Hunt by 19 percentage points in what is routinely described as "a battle of the titans" and "the second most important race in the nation in 1984."

"This is the race of the century for the people involved," said Joseph W. Grimsley, who is expected to become Hunt's campaign manager. "This is the closest opportunity this generation will have for the progressive New South to replace the racist, negative Old South. It's a truly transitional event."

Helms has tried to narrow the gap by spending between $27,000 and $50,000 a week on advertising since April, according to campaign finance reports.

"The North Carolina registration ratio is something like 3 to 1 against any conservative or Republican," he said here last weekend. "On top of of that, the editors of all the major daily newspapers in this state are very liberal. They are not inclined to give any balance. So we have to buy anything the Democratic opponent gets free."

Seldom does a political contest present such a clear choice.

Helms, 61, is one of the nation's leading conservatives, the archangel of the New Right in the Senate, chairman of the Agriculture Committee.

He is an ideologue who is anti-Washington, anti-union, anti-communist and anti-government.

As for the Korean airline incident, he said: "I can't talk about it without almost weeping."

Yet he manages to talk about the incident at almost every stop. His tale is eloquent, laced with the same kind of raw emotion that made him a successful television commentator and helped him win two Senate elections.

Helms tells how he and his wife were on "the right plane" for Seoul because Tom Landry, coach of the Dallas Cowboys, had invited them to a fund-raising dinner in Texas. They caught a later Korean Air Lines flight out of Los Angeles. His plane refueled in Anchorage at the same time KAL 007 was refueling.

Helms met a young mother reading a Bible to her two small daughters, age 3 and 5, in the airline lounge. He gave the girls some candy, placed the younger one on his knee and played a game with her he plays with his own grandchildren.

When KAL 007 was ready to leave, "the little girl kissed me on the cheek," and boarded the plane with her mother, Helms recounted here, his voice choking with emotion. In a moment, he recovered his composure. That was the last time that he saw her, he said.

"I may be paranoid. I may be obsessed, but I think if there was ever a time to nail the communist hide to the wall, it is now," he said. "No Samantha, they are not folks just like us. They are cruel, barbarians. They will do anything to destroy freedom."

The crowd of 600 roared its approval.

Neither Hunt nor Helms has announced candidacy, and they aren't expected to until January. Meanwhile, Hunt, recuperating from a recent gall bladder operation, is trying to stay above the Senate battle.

"I'm just working hard as governor," he said.

Hunt's advisers plan a campaign geared to their candidate's strong suit: his popularity as governor and his interest in state rather than national issues. Let Helms talk about communism and abortion, they say. Hunt will talk about education and economic development.

"I'm concerned about the state of North Carolina being properly represented by someone who puts North Carolina first," Hunt said in an interview. "Someone who can work with other people to get the job done . . . . We need effective leadership for the state, not national groups representing the right, the left or the in-between."

Hunt, 46, is the state's most popular Democrat, a second-term governor who emerged as a major player in national party circles by heading the commission that attempted to overhaul the party's nominating procedures. He is a moderate-progressive, a pragmatist who wants to make government work.

Both, however, are extremely skilled politicians.

Helms is an innovator in modern campaign technology, creator of the nation's most successful political action committee, the National Congressional Club, a man able to raise millions for his pet causes and candidates. Hunt is a coalition-builder who has assembled a well-oiled statewide political organization of traditional Democrats, women, labor and teachers.

Their race is likely to be most expensive Senate contest in history.

Helms' campaign raised and spent $1.7 million during the first six months of 1983, and Hunt aides predict that Helms will raise $14 million--an estimate Helms backers dismiss as an exaggeration.

Hunt's aides last year estimated that they would raise $10 million, which they have scaled back to $5 million. The Hunt-related North Carolina Campaign Fund raised $1.3 million and spent $724,000 in Hunt's behalf during the first half of 1983, according to Federal Election Commission reports.

The campaign has been under way for months. The Helms for Senate Committee has a staff of 30, including a black press secretary, Claude Allen.

The Jim Hunt Exploratory Committee opened a storefront headquarters a block from the statehouse in August with a staff of six. It has retained pollster Peter Hart, media expert David Sawyer, and Craver, Matthews, Smith & Co., a direct-mail fund-raising firm.

Each side accuses the other of demagoguery and name-calling. A fund-raising letter last fall from the North Carolina Campaign Fund, for example, called Helms "a dangerous right-wing demagogue," "an unscrupulous campaigner," "the most vociferous advocate in Congress of every far right position," and a man of "religious and racial intolerance."

The Helms campaign began striking back in April, 18 months before the election, with a series of hard-hitting newspaper, radio and television advertisements. They have continued since in what one observer calls "a form of Chinese water torture."

Some are positive, showing President Reagan, Senate Republican leaders and Tom Landry endorsing Helms. Others, in small daily and weekly newspapers, accuse Hunt of being a tool of liberals.

One pictures Sen. Edward M. Kennedy (D-Mass.), civil rights leader Jesse L. Jackson, Georgia state Sen. Julian Bond and former vice president Walter F. Mondale as "Jim Hunt's Political Machine." "Ask yourself--why are these liberal politicians behind Jim Hunt?" it said.

But the questions are, do people really care about an election more than 13 months away? And will they be bored to death by the time the election rolls around?