The "Pride in Tobacco" cocktail party held here last week on Maryland's tobacco-growing coastal plain was called to silence only once. Ruddy-faced tobacco farmers stopped pouring down the free whiskey, and Maryland state legislators stopped eating the free crabmeats as the 250 people strained to hear a man from the R.J. Reynolds Tobacco Co.

"The good news is we have not run out of booze, and we have not run out of food," announced Charles A. Tucker, vice president of public affairs for the nation's largest cigarette manufacturing company. The bad news came later, in a private conversation with a reporter.

"If worse comes to worst, I can see a long, slow decline for the tobacco farmer and the tobacco industry in the United States," allowed Ron Sustana, another Reynolds vicep president at the party in the Rod-N-Reel Restaurant on the western shore of Chesapeake Bay.

The tobacco farmer and the tobacco industry in the United States are on the defensive. There has been a steady decline in tobacco use in the last decade, according to the Department of Agriculture, and last year adults in this country consumed less tobacco per person than they have in any year since 1898.

People in the United States smoke less today because they believe that smoking kills, government officials say. Recent studies indicate it is dangerous even to be in the same room with smokers. The World Health Organization last week chose smoking as its top prority for 1980 because "smoking is probably the largest single preventable cause of ill health in the world."

Congressmen from tobacco states concede it is becoming increasingly difficult to fight back against anti-smoking legislators who attack the tobacco industry. A proposed bill to ease the federal budget crisis by sharply increasing federal cigarette taxes has received strong support on Capitol Hill this spring. Even Secretary of Agriculture Bob Bergland, the man in charge of the tobacco industry's beloved price-support program, says if he had the power, he would ban-smoking.

"The tobacco industry is facing adversity. In that type of situation, you pull the troops together," said Horace Kornegay, a former North Carolina congressman who now heads The Tobacco Institute, which speaks for the industry in Washington.

R. J. Reynolds last year spent nearly $250,000 trying to pull the troops together at "Pride in Tobacco" parties like the one held here last week. Literature chock-full of pro-smoking statistics was distributed. Free cigarettes, pipe tobacco and chewing tobacco were handed out. Unity was championed.

"The people who grow tobacco have a lot to be proud of," John S. Cousart, a public relations man from R. J. Reynolds, said during the party. He explained that farmers and warehousemen are carrying out a great American tradition; that they are helping contribute to the economy, and that along with the rest of the tobacco industry pay nearly $6 billion in taxes.

While those are things to be proud of, tobacco people at the party said there is one new trend in the industry to be optimistic about -- sharp increase in Third World demands for cigarettes.

The Tobacco Institute and the Washington-based Tobacco Associates, which represent tobacco grower, agree the only growth potential for tobacco lies outside the United States. "We need the world," says Kirt Wayne of Tobacco Associates. "The blended cigarette, which relies on high quality American tobacco, is growing in popularity around the world."

As the cigarette industry (which is dominated by seven multinational tobacco conglomerates) rejoices over the new market, health authorities and Agriculture Secretary Bergland are troubled that the continued health of the nation's tobacco industry may dependon the exploitation of potentially deadly habit.

"The threat to many developing countries is immediate and serious," according to a World Health Organization report. "In the absence of strong and resolute government action, smoking disease will appear in developing countries before communicable disease and malnutrition have been controlled, and the gap between rich and poor countries will thus be further expanded."

Bergland and John M. Pinney, director of the government's Office of Smoking and Health, say there is not much the federal government can do about tobacco exports.

Tobacco farmers and cigarette manufacturers, while pleased with over-seas sales, say they still must rely on tobacco-state legislators in this country to defend them from anti smoking crusaders. But the lawmakers say it's becoming tougher to play defense.

"If at all possible, I would prefer not to take tobacco legislation to the house to avoid potshots from anti-smoking legislators," says Rep. Walter B. Jones (D-N.C.), chairman of the House subcommittee on tobacco.

Tobacco-state legislators have given up arguing the health issue and are forced into vote trading in Congress.

"Those of us who have come to Congress in the past 10 years from tobacco states have had to try to make up for our lack of numbers with fancy footwork and agility," says Rep. Charles Rose (D-N.C.). He recalls how lawmakers from North Carolina, Virginia , Kentucky, South Carolina, Georgia and Florida banded together to help bail New York City out of its financial problems two years ago with the understanding that "the New York boys" would go easy on tobacco.

"We have told the New York boys that we would help them with their issues, but we want them to understand that they weren't voting for sin and cancer when voting for our tobacco program," said Rose.

While tobacco advocates on the national level have had to resort to fancy footwork subtleties are not needed in tobacco-growing states like North Carolina.

"The politicians here who isn't 100 percent for tobacco and the tobacco farmer is a goddam fool," says Sam McLawhorn Jr., a former tobacco farmer, member of the North Carolina Board of Agriculture and chairman of the Pitt County reelection committee for Gov. James B. Hunt Jr.

Gov. Hunt, who was born on a tobacco farm and still raises the crop in eastern North Carolina, has pledged himself to work 100 percent for tobacco. The tan, unmarked state police car that hauls him around North Carolina bears a "Pride in Tobacco" window stickers provided by R. J. Reynolds. Last month, in an example of a politician belaboring the obvious, the governor's campaign newspaper carried the banner headline: "Hunt Says Tobacco is Number 1."

Hunt, who's trying this year to become the first governor in the history of the state to succeed himself in office (the state constitution recently was changed to allow this), has chosen to make an issue out of whether he or his opponent in the may 6 Democratic primary loves tobacco more. Hunt has impugned former Gov. Bob Scott's love of the plant by circulating a remark Scott made when he was governor 11 years ago.

"It is time to destroy the myth that tobacco is king in North Carolina," Scott said in 1969 in a speech calling for a more diversified economy and the state's first retail tax on cigarettes. North Carolina, which still has the lowest tax in the country (2 cents a pack) is the nation's leading tobacco state, with annual tobacco sales of about $1 billion. The tobacco industry contributes an estimated $6.6 billion to the state's economy each year, according to state figures.

Ironically, for all his pro-tobacco rhetoric Hunt has "done all the things you do when you believe that tobacco is not king," according to Ferrel Guillory, the chief editorial writer for the Raleigh News & Observer. The governor has been a leader in diversifying that state's economy by attracting new industry into places like Pitt County, the premier tobacco-producing county in the nation and a rural area where tobacco long had been the only money maker.

While Hunt's electioneering may not square completely with his record as governor, his tactics seem to be working in Pitt County. Farmers interviewed there said recently they remain unwilling to trust a politician who would put down tobacco. "That Scott fella seems sneaky to me," said Ervin Mills, a tobacco farmer in Blackjack.

In North Carolina, king tobacco has the clout to pressure health groups like the American Cancer Society and the American Lung Association into conducting antismoking campaigns that are far more muted than in the rest of the country. "No Smoking" signs are rare in North Carolina, as are no-smoking sections in restaurants. Even the powerful Baptist Church feels the pressure.

Cecil Gaskins, a North Carolina tobacco farmer who makes $60,000 a year, tells the story of the preacher at his Ballards Crossroads Independent Missionary Baptist Church who was preching Sunday after Sunday on the evils of smoking.

Gaskins, who thinks so highly of tobacco that he's already had a tobacco leaf carved on his own tombstone, tolerated the preacher as long as he could. Finally, the farmer stormed out of church one Sunday. After the congregation had filed out, Gaskins charged back for a final word:

"Don't go preachin' 'gainst back-uh. Ever' cent of money I have put in this church was from 'back-uh."

And Gaskins threatened never to give the church another cent unless the sermon "laid off 'back-uh." Although the Rev. Dewey Allen, Gaskins' pastor, says he doesn't "exactly" recall the incident, he does sayt that smoking rarely comes up anymore in his sermons.

Tobacco farmers in North Carolina say they're confident that politicians and most everybody else in the state won't mess with tobacco interest, but they're worried about the politicians outside of the South.

"We always got that fear that something awful is going to happen (to the USDA program that keeps tobacco prices high), says farmer Gaskins. "We try to block out that fear, but there ain't a farmer alive who hasn't sat back and thought about what might happen in Washington."

The farmers have cause to worry. The federal government including the Department of Agriculture, which spends about $337 million a year on pro-tobacco programs, has become increasingly skittish about tobacco.

Agriculture Secretary Bergland, theis year stopped the government from shipping tobacco to poor countries under the "Food for Peace" program. Until Bergland stopped the shipments this year, between $17 million and $66 million a year in tobacco had been sent during the past decade to countries such as South Vietnam, Cambodia and, most recently, Egypt.

Bergland, who doesn't smoke stopped the shipments because he said tobacco doesn't belong in a food program. The shipments had been used to dispose of unwanted government owned tobacco surpluses.

In the past two years, president Carter's budget makers have proposed the elimination of research funds for tobacco production. Tobacco-state lawmakers have managed to restore the $3.1 million in research spending, but two-thirds of it is now spent on developing low-tar-and-nicotine cigarettes.

Early this month, Rep. Robert F. Drinan (D-Mass.) proposed a 10-cent increase in the federal excise tax on cigarettes, an increase he said would add up to $3 billion to the federal budget. Drinan, an antismoking advocate in the House since 1975, said the tax increase would raise cigarette prices and should price some smokers, paticularly teen-agers, out of the habit.

Drinan's proposal was front-page news in North Carolina and spokesmen for R. J. Reynolds and the Tobacco Institute say the proposed tax increase is particularly worrisome because Congress clearly needs to find more money for a balanced budget in 1981.

Sen. Herman A. Talmadge (D-Ga.), a defender of tobacco in the Senate for 23 years, says he and his tobacco land compatriots are confident they have enough seniority and key committee assignments to repel the "much stronger vendetta against tobacco than we have had heretofore.

"I'm still chairman of the Senate Agriculture Committee and I don't think that is very weak," Talmadge says.

Tobacco-state legislators hold influential positions on agriculture and appropriations committees in both the House and Senate. Six of the seven members of the House tobacco subcommittee are from major tobacco states.

Three years ago, the lawmakers from tobacco country demonstrated they still had the muscle to protect their interests. Rep. James Johnson (R-Colo.) at that time annouced that it was schizophrenic for the government to subsidize tobacco growers and at the same time spend money to warn smokers about the danger of cigarette smoking. He had planned to offer an amendment ending tobacco price supports, but he suddenly changed his mind.

The word among the tobacco legislators was that he had been, as one Southerner put it, "beet-en down." Johnson, who represents a leading sugar beet farming district, was told that the future of a sugar beet subsidy rested on his willingness to shut up about tobacco.

Rep. Rose explained it more delicately at the time: "He wanted help on his sugar problems. We wanted help on tobacco. We convinced him to modify his position."

With most tobacco-state legislators confident that they can protect the tobacco price-support program for at least the next decade, the key questions appear to be who is going to smoke the stuff.

The HEW Office of Smoking and Health predicts the number of smokers in the United States will drop by between 10 million and 15 million in the next decade. Overseas sales of tobacco, while offering a potentially lucrative market to the tobacco industry, would be hard pressed to absorb the loss of the American market.

Pinney, of the Office of Smoking and Health, predicts that the decline in smoking in the United States and other developed countries will eventually spell doom for the tobacco industry and force the tobacco-growing states from their dependence on the weed.

"The ultimate demise of the tobacco industry has a long latency period, just like the latency period for smoking-related diseases," says Pinney.