Lewis du Pont Smith, a young heir of the wealthy du Pont family, didn't consult his relatives in 1981 before he invested $80,000 in a walnut grove business, only to lose it all. Family members became more concerned when he lost a $23,000 investment in a silver bullion scheme, and then sank an additional $74,000 into declining stocks on the Canadian stock exchange, according to court documents.

But when Smith announced last year that he was joining the organization of political extremist Lyndon H. LaRouche Jr. and was thinking about giving the group all his $1.5 million in savings, family members said, they decided it was time to act. They asked a judge in suburban Philadelphia to declare Smith incompetent to handle his finances.

In November, Chester County (Pa.) Common Pleas Judge Lawrence E. Wood agreed, ruling in a preliminary finding that Smith, 28, is "mentally ill." The judge based his decision in part on Smith's statements in support of the apocalyptic message of LaRouche. He said Smith is legally an incompetent who is "not equipped to deal with his financial affairs," and named a guardian to oversee his finances until the judge issues his final ruling.

Now Smith -- who lives in Leesburg, sells advertisements for a LaRouche newspaper and is vigorously defending his mental state -- is at the center of a courtroom battle that could make legal history concerning the constitutional rights of members of unpopular political or religious groups and alleged cults.

In addition to the existing decision naming a guardian over Smith's money, his parents, who live in Paoli, Pa., are asking a Pennsylvania court to rule that he needs a guardian to care for him personally. Such a guardian could remove Smith from the organization and arrange psychiatric help.

"I am not mentally incompetent," Smith said last week, reading from a written statement. "I have no history of mental illness. The only reason that my family alleges that I am ill is that I propose to spend my money in some fashion other than the obscene way in which they spend theirs."

While dozens of families have tried to use the courts to remove relatives from so-called cults to be "deprogrammed," very few have been successful, legal specialists said. Smith's lawyer, James Crummett of Philadelphia, said the case is unprecedented in a number of ways.

Lawyers said they know of few cases in which someone has lost control of his funds for giving money to an alleged cult.

Under Pennsylvania law, one definition of incompetency is that a person is being exploited by "designing persons," and in this case the judge said people have designs on Smith's money. Crummett said there has never been a case before this one in which a political group such as LaRouche's has been found to be a "designing" party.

Jeremiah Gutman, a New York attorney who specializes in civil liberties cases, said that in the past some families have persuaded judges to issue guardianship orders to remove a relative from an alleged cult. But Gutman said the judges ruled without telling the group member about the hearing, out of fear the member would go into hiding. No family has ever succeeded in getting a guardianship order when the relative is present in court, he said.

The legal war pits an enormously wealthy family against a young man described by his lawyers as a sheltered son rebelling for the first time against an oppressive family atmosphere.

The outcome of the legal battle could mean big money to the LaRouche organization, because a Smith victory would allow him to give or lend his money to the group.

Former LaRouche associates who do not want to be identified have said that LaRouche supporters often have been heavily pressured to give all their money to the group. Prosperous supporters have emptied trust funds for the group, they said. But Smith appears to be by far the wealthiest follower in its history.

Smith's lawyers say he should be able to spend his money any way he pleases, and deny he ever said he would give all his money to the LaRouche organization.

"Historically, men of wealth have substantially reduced their fortunes in the support of political and/or philosophical causes without being declared incompetent," Crummett said in a court document. He cited a 1905 Pennsylvania court decision saying "a man . . . may beggar himself and his family if he chooses to commit such a folly."

Smith's story is also a case study of the difficulties confronted by many families of LaRouche followers, former LaRouche associates said. Ex-associates said that the group discourages contact with relatives, and that most members are estranged from their families.

Former associates said LaRouche, a Marxist in the 1960s who later moved to the right, holds considerable sway over supporters. He denies the group is a cult.

LaRouche told supporters in an internal report several years ago that "your parents are immoral . . . . Everything your parents say is evil -- they are like lepers, morally and intellectually insane."

On Nov. 12, Judge Wood issued his preliminary ruling that Smith is incompetent, after Smith had lent a LaRouche group $212,000. Smith testified that he would not be upset if he wasn't paid back.

Wood's finding is the first step in a two-step process, and the family and Smith are scheduled to argue the requests for guardianship before the judge on June 23.

If Wood and higher courts uphold the guardianship ruling, Smith would lose control of his fortune, except for living expenses. Currently, he has about $1.5 million, and receives more than $200,000 a year in interest from several trusts set up by his mother's father, Henry B. du Pont II, according to court papers.

A 1974 history of the du Pont family said that his grandfather had $200 million when he died in 1970.

Recent magazine articles have said that Smith's mother, Margaret du Pont Smith, controls a fortune of about $150 million. But Smith's father, E. Newbold Smith, said that figure is vastly overstated.

Smith and his father both declined to say how much money Smith eventually would have in his trusts. A knowledgeable source said the trusts will "yield to him more than a reasonable person could spend in a lifetime."

A year ago Smith's father wrote for advice to William Weld, the U.S. attorney in Boston, whose office is conducting an investigation into alleged credit card and income tax fraud by LaRouche associates. No charges have been brought.

The father wrote, "The sum total of what the LaRouche followers really mean is gibberish, and the purpose is to get your money and end up owning you as a slave." He called his son a "gullible young schoolmaster who has been in the throes of a nervous breakdown."

As a child, Smith suffered dyslexia, a reading disability, and had trouble in school, according to court papers. He was especially bad with numbers, but was otherwise normal and outgoing, the papers said.

A star athlete at his private high school -- he is 6 feet 5 inches, and weighs about 230 pounds -- he received a football scholarship from the University of Michigan. A sports injury flared up before the season began, and doctors told him he should not play football again. He was upset, said his brother, Stockton Smith of Norfolk.

"He lived for athletics," said Stockton Smith. "It took his lifelong ego satisfaction away. He had nothing to fall back on."

While Smith received a letter in wrestling one year, he became unhappy in his college years, said people who know him. After graduating in 1980 with a degree in general studies, he coached and taught at private schools in Pennsylvania and Connecticut. But he did not do well at the jobs, and was asked by at least one school not to return, according to court testimony.

Court papers and interviews with people who know Smith tell the story of his conversion to the LaRouche movement:

He first met LaRouche supporters at Philadelphia International Airport in the spring of 1983. The LaRouche people apparently learned about his wealth because in early 1984 a LaRouche group "economics analyst" advised him about stock investments.

That summer, which Smith spent with his family in Maine, LaRouche fund-raisers continually telephoned the family home, but he angrily refused their calls.

That fall, he was foundering in his new job teaching American history at Friends Central School outside Philadelphia. He contacted the LaRouche group because he wanted to use alternative texts, and recalled the group had written about American history. He became fascinated with its writings. But when he started using LaRouche publications in the classroom, school officials said, they told him to stop.

Smith testified that soon he "became fully immersed in the research and activities of the organization."

Family members said they didn't like what they saw. Wood said in his decision that as Smith became more involved with LaRouche, his personality "started to change . . . . He went from being a friendly, 'happy-go-lucky' sort to being a serious and withdrawn person hostile to his family."

Smith wrote angry letters home in early 1985. In one letter to his father, Smith denounced the media's "bloody, oligarchical" conspiracy, and attacked his father's "pagan" views. He wrote that if his father wanted to understand his new thinking, he should "start reading and digesting the material I give you."

Around the same time, in a two-month period in early 1985, Smith lent a LaRouche group $212,000, all of it unsecured. The group gave him loan documents on only $142,000 of the $212,000, and he initially couldn't even recall the additional $70,000 loan when questioned in court. Smith testified he "wouldn't have been crushed" if he wasn't repaid.

The Smith family took action in April 1985 after learning that Smith intended to wire LaRouche people an additional $75,000 to help them set up a WATS telephone line in Leesburg for fund raising, according to court papers filed by the family.

That is when the Smiths -- his parents, two brothers and a sister -- filed a court petition to have him declared incompetent. Judge Wood issued an order barring him from transferring any money to political or charitable groups without the court's permission. Wood then held hearings over seven months, and in November made an initial ruling that Smith is incompetent.

"He has a disorganized mind and compensates by setting up an oversimplified view of the world in which he is one of the good guys and 'they' are conspirators bent on mischief," Wood wrote. "As such he would be and has been an easy target for anyone who pretends to support him in his efforts to combat the bad guys . . . . He no longer has the ability to 'choose' in either a knowledgeable or totally voluntary way."

The judge summarized the conclusions of two psychological experts testifying for Smith -- that he suffers "a mental disorder" and "a mixed personality disorder with inadequate and immature features." A psychiatrist testifying for the family said he is mentally ill. The psychiatrist, David Halperin, pointed to a number of Smith's statements as evidence that Smith has "delusions of persecution" and that he believes the world "consists of continual crisis, continually a threat." The statements essentially reflect the LaRouche group's belief in conspiracies.

Wood said in his ruling that the LaRouche group is "a political organization with unusual, if not suspect, goals and motives." He wrote that Smith is "a target for designing persons and is liable to dissipate his assets, and requires the protection of the court."

Wood named the Wilmington Trust Co. as guardian over Smith's money, but has allowed him to receive $5,000 a month for living expenses. In addition, he allowed Smith to buy a $128,000 house in Leesburg, where he lives with other LaRouche followers.

But the family says Smith's mental condition is worsening with time in the group.

They allege that the LaRouche group has "acted to further alienate" Smith from his family by "limiting personal and telephone contact." The family says it does not have Smith's phone number.

Several months ago, when a relative died, family members got a message to Smith through a LaRouche office, and he called back, lawyer Crummett said. But in the telephone conversation, Smith told his mother that "the LaRouche organization has forbidden him from discussing any matter with his family other than the weather," according to a court document filed on behalf of the family.

Smith and Crummett both said that it was Crummett, not the group, who told him to restrict conversation to the weather because of the pending litigation.

Crummett, whose fees are paid out of Smith's savings, said that, given the fact that his family has taken him to court, avoiding family members "would certainly not be abnormal."

Court papers indicate the family will try to prove that the LaRouche group has control over Smith. Smith's behavior recently has become "increasingly unsocial, aberrant and at times violent," the family said in court papers.

The Smiths' court papers cite as evidence the fact that a federal magistrate in Alexandria found Smith guilty of simple assault and unpermitted touching of another person in connection with two incidents last year at Dulles International Airport, where Smith was distributing LaRouche literature. He is appealing the January convictions.

U.S. Magistrate Leonie M. Brinkema said in her ruling that last Aug. 22, Smith lunged at a man with whom he was arguing. Smith pushed him about 10 feet, grabbed him and pinned him face down on the floor, she said. The man suffered minor rib injuries and bruises, she said.

On Oct. 3, Smith yelled at a woman at the LaRouche table, and told an extremely obscene story about a woman that she said was directed at her, the judge said. When the woman reached for his solicitation permit, Smith grabbed her arm, the judge said.

Brinkema sentenced him to one year's probation and fined him $200.

Smith's lawyer, Crummett, said that the convictions are not evidence of mental illness, and that association with an unpopular movement is not either.

Some unpopular groups, such as the antislavery and women's suffrage movements, "later became the majority view," Crummett said in an interview. "Anybody who went to their meetings, maybe all their families thought they'd gone crazy, too."

Smith said that "there is only one issue involved in this case, and that is whether I as a citizen of the United States have any constitutional rights . . . . My family seems to think that because they are du Ponts they have the feudal right to determine with whom I associate and for what I spend my money."

Back in the neighborhood around his house on Loudoun Street in Leesburg, neighbors say Smith is a "super nice," cordial man.

The LaRouche people who live with him come and go to work at nearby LaRouche offices all night long, neighbors said. When they are not working, classical music and singing can be heard from the house, they said.

Smith said that one upsetting result of the judge's ruling is that it prevents him from voting and marrying the woman he loves. His family is showing "arrogance of power" characteristic of the du Ponts, he said.

"They are used to having their way, regardless of laws," Smith said. "I feel sorry for my family as I would for any misguided and disturbed souls.