Four years ago the Libertarian Party was just another obscure fringe group, an odd collection of crewcut former Goldwaterites, black-shirted radical anarchists and aging veterans of Sen. Eugene McCarthy's "Children's Crusade."

Striving for recognition alongside such political lightweights as the Socialist Workers Party, the Prohibitionists and the American Party, the underfunded and poorly organized Libertarian Party saw its presidential candidate gather a mere 175,000 votes nationwide.

This year the party is making a serious bid to leap into the American political limelight. Its 1980 presidential hopeful, three-piece-suited Los Angeles corporate lawyer Ed Clark, has a $3.5 million campaign budget and a slick, well-organized media operation. Clark predicts he'll capture several million votes this November as voters are turned off by both major-party candidates.

"More people think of themselves as independents than Democrats or Republicans already," said David Bergland, national party chairman and a business attorney from Orange County, a hotbed of Libertarian activity south of Los Angeles. "What we're seeing at an accelerating pace is the breakup of the two-party system. People are saying to hell with it. The old parties don't stand for anything."

Libertarian Party leaders were greatly heartened by their successes during the 1978 off-year elections, when their candidates for offices ranging from local representative to U.S. senator polled more than 1.5 million votes, including some 400,000 for Clark's gubernatorial campaign in California. In Alaska, a Libertarian won election to the state House of Representatives, thus becoming the party's sole officeholder.

Bergland predicts that the Libertarians will acheive even greater victories in 1980. The party, which may field as many as 600 candidates for various offices nationwide, has a platform calling for drastic tax reductions, abolition of virtually all government interference in economic and personal affairs, and opposition to draft registration and military adventures overseas.

Libertarians come to their ideology from what sometimes appear to be diametrically opposed directions. Their passion for the laissez faire economics of Adam Smith and Milton Friedman has drawn Republican conservative lawyers and small businessmen to their ranks. At the same time, the party's strong bias for individual liberties has attracted proponents of alternative lifestyles, including gays, nudists, onetime hippies and miners from the wilderness of Alaska.

But whatever their personal path, most Libertarians feel a deeply American heritage, tracing their ideology to such revolutionary thinkers as Thomas Paine and Thomas Jefferson. For them, the human rights precepts for the Declaration of Independence and the Bill of Rights are still relevant in the complex society of the 1980s.

The party's move into the political mainstream has been funded largely by Charles Koch, heir to a large oil and industrial fortune in Kansas. Koch already has spent several million dollars on various Libertarian projects, foundations and publications. His brother David is running as the party's vice presidential candidate, largely in order to take advantage of a campaign law loophole that allows candidates to pour large sums of their own cash into their national campaigns.

The influence of the Kochs and their associates disturbs some who helped found the party in Denver in 1972. Some are concerned that the party's leaders, in their desire to win new adherents, may be abandoning principles.

"As things grow, things happen. People you disagree with are in power," said John Hospers, a University of Southern California philosophy professor who drew 5,000 votes as the party's 1972 presidential candidate.

Hospers and others are particularly worried about the influence of the Koch-funded CATO Institute, a San Francisco-based Libertarian think tank, on party leaders and platform. They accuse the institute of encouraging the party's increasing trend toward an anti-interventionist foreign policy including an American withdrawal from the North Atlantic Treaty Organization and a suspension of arms sales credits, even to such allies as Egypt and Israel.

"They're really trying to appeal to the Left on defense," said New Hampshire Libertarian chairman Jim Pinard. "Clark is saying we shouldn't be in any alliances, but that's difficult in the world we live i today. I think his position could turn off a lot of people."

Libertarians also are concerned that the candidacy of Rebublican Ronald Reagan, who espouses some Libertarian ideas on the economy, could drain votes away in November.

"In a Bush-Carter race it would be conceivable we could carry this state," said Alaska state Rep. Richard Randolph. "Reagan, however, is very popular here. Alaska hates Carter. Reagan they don't know enough about to dislike."

Bergland, however, believes a Carter-Reagan race could play into the Libertarians' hands, at least in most states. While President Carter is widely detested for his bungling of the economy, Bergland maintains, Reagan is against abortion, gay rights and marijuana decriminalization -- positions that are anathema to many potential Clark supporters, particularly those under 40.

Reagan, Bergland said, "talks about free enterprise and reducing taxes, but his history as governor of California is exactly the opposite. To him free enterprise means government breaks for business. He wants to enforce all the victimless crime laws. Reagan's just a big PR package."

Some party officials maintain that a possible third party candidacy by Rep. John B. Anderson (R-Ill.) provides a far greater threat to Clark's status as the leading protest candidate of 1980.

"It would be very discouraging if [Anderson] ran," said Ed Crane, a top Libertarian strategist. "It's really a shame that a guy with his kind of record is so misperceived by the public. He's a middle-of-the-road nothing. He's what Congress has been doing -- he is the problem."

Presidential candidate Clark, however, remains aloof from worrying about the other candidates. He said he's encouraged by the warm reception his campaign has received across the nation from both the public and the media.

Clark and his advisers believe media exposure might prove the key to his success, and are pushing to be included in any possible presidential debates this fall.

While acknowledging that the Libertarians have some appeal to voters, officials of the major parties dismiss the seriousness of the Libertarian Party's challenge.

"Their basic weakness is their philosophy, which is to do away with government. If they moderate, maybe they could do something," said W. J. (Bill) Thom, chairman of the Orange County Democratic Party. "They will be a force like the American Independents were, but it's fluid. I don't think they'll last very long."

Libertarian activists, not surprisingly, refuse to accept this view. They are out working the beaches and suburban tracts of Southern California, registering the gays in San Francisco and enlisting the support of disgruntled miners in the wilds of Alaska. Most are convinced that the tide of political opinion is rolling towards the Libertarian Party.

Dan Mahaffrey, a 31-year-ole machine shop owner and Libertarian candidate for city council in Huntington Beach, an Orange County seaside town, believes the electorate, particularly younger voters, is fed up with government regulations that affect their personal lives and their economic activities.

Using volunteer help to canvass the beaches, Mahaffrey's campaign organization has helped register more than 6 percent of the town's 90,000 voters under the Libertarian label.

"The baby boom generation like me, we're making it now," he said as he handed out literature on a palm-shaded suburban street. "People now just want to be left alone so they can make their money. That's what the voters are going for and that's why they'll end up coming to us."