Eight Mexican families, shedding the safety of obsecurity treasured by most illegal aliens, have turned to the courts in an effort to gain new rights for themselves in America despite their illegal status.

By challenging a Texas law denying free public education for illegals, the families and their lawyers have raised a fundamental constitutional question that, regardless of the outcome in lower courts here in Texas, is virtually certain to be presented to the U.S Supreme Court for the first time.

That issue: To what extent do the constitutional guarantees of due process and equal protection of the laws apply to people living in the United States illegally?

How this issue is eventually resolved will determined whether uncounted thousands of Mexican children in the state, many of them poor, will have access to a free education and whether Texas school systems will have to accept them, at a cost some schools estimate in the millions.

Lawyers for the state and two school systems argue that the children have no such rights to an education and that to provide it would take limited resources away from U.S. citizens and alliens living here legally.

Attorneys for the families argue that the Constitution refers to persons - not citizens. They also say that the children for whom education is the key to a better life, are innocent victims of the Texas law, whatever the illegal actions of their parents in bringing them to the United States.

Already the cases challenging the law - one in federal court in Tyler, Tex., and one in state court against the Houston schools - have produced their ironies: aliens who came illegally to this country going to court seeking enforcement of constitutional rights, and the state of Texas, which has a $3 billion budget surplus, citing limited resources to spend on education.

Both efforts are being carried out with special considerations for the illegal aliens inherent fear of exposure to deportation. In Tyler, U.S. District Court Judge William Justice has ordered records sealed to protect the families identities, and in Houston a verbal agreement promises no retaliation against the families here.

"These people live an underground life. They are afraid of their shadows," says Peter Roos, director of education litigation for the Mexican American Legal Defense Fund, which represents the Tyler families.

The challenge in federal court has been success so far, giving the Tyler children temporary free admission to school pending further court hearings. The Houston challenge lost in a state district court and was argued on appeal early this month.

"A distinct class of poor, undocumented children ... is aboulutely deprived of any education whatsoever by virtue of their poverty." Judge Justice said in ordering the Tyler schools to admit 16 children without charging tution. "This kind of total deprivation considered by the Supreme Court," said the judge in rejecting the argument that the equal protection clause of the Constitution does not apply to illegal aliens.

On another level, the two-year-old Texas law is seen by some immigration lawyers as paart of yet another turn in this nation's cyclical moves against aliens through restrictive legislation. Previous laws were aimed at the Chinese, Japanese and southern Europeans. This time it is illegal alliens overwhelmingly Mexican, who came to the United States by the hundreds of thousands in search of jobs they could not find in their homeland, at a time of high U.S unemployment.

"It's a recurrent thing that pops up every time there is a soft spot in the economy." says David Carliner, a Washington attorney who specializes in immigration law and is general counsel to the American Civil Liberties Union. "And while the racist language of the past is gone, the effect is completely anti-Mexican."

He notes that 20 states have passed laws making it a crime for employers to hire illegals and that the Carter administration has proposed such a national law.

The Texas law on free public education, adopted in 1975, says that the state will both provide money to local school districts for the education of illegal aliens, but only for citizens and for aliens here legally. Since state funds provide the bulk of education resources, many schools were permited to charge tution for illegals.

In September, 1975, when 12 Houston illegals tried to enter school, they were told to either prove they were in the country legally pay $90 a month tution. In the tiny Mexican-dominated neighbourhoods of east Texas where church services may be held in Spanish and Mexican food and newspapers are sold, the families could not afford the tution, and the legal challenge began.

At a hearing, immigration officials estimated that 4,120 to 5,626 illegal alien children of school age lived within the bounds of the Houston school district, part of a total illegal alien population in the same area of 187,500. A school official then estimated that educating those children would cost $4.1 million to $8.3 million. The school district has 233 schools serving 207,000 children, with an operating budget this year of $264 million.

Peter D. Williamson, the attorney for the Houston children, challenged the state law on the constitutional grounds and also said it was an attempt to regulate immigration - a power belonging to the federal government.

Kelly Frels, a lawyer with the prestigious Houston law firm of Bracewell and Patterson, represented the Houston schools and joined the state attorney general's office in defending the state law. They argued that there is no absoulte right to a free education, that the Supreme Court has never extended the 14th Amendment to illegal aliens, and that the state was not infringing on federal immigration powers.

Essentially the same arguments have been made in Tyler, where the schools waited two years before implementing the state law.

Fearing that it might become a haven for illegals, the school district cracked down this summer. Last month, illegal children tried to enroll free, were unable to pay the $1 of annual tution, and were denied admision. The Mexican-American Legal Defense Fund intervened and, representing 16 children, took the 16,000-pupil Tyler schools to federal court.

The fund's Peter Roos challenges the schools' and the states' financial arguments by submitting evidence that the children's parents are taxpayers even if they are here illegally. Roos also notes that in the 1976-77 school year the Tyler schools educatied about 50 illegal alien children and that when those children were barred this year, there were no cuts in the teaching force and no reduction in school spending.

While Texas is apparently the only state to have a law banning free public education for illegals, it is not known to what extent school systems across the state are complying with it. The schools merely report their average daily attendence of eligible students to the state for reimbursement of costs. Illegals who are not challenged to doucment their status by school authorities may very well be enrolled in public school.

Regardless, the outcome of these two cases is viewed in border terms by both sides.

"It is going to be very important to the country," says John Hardy, the lawyer for the Tyler Schools, who sees the decision determining whether the nation "Opens the floodgates" to illegal aliens. Illegals "are not entitled to the same rights you and I are," he says. "And government is not required to provide the same rights as for those here legally."

For his part, Roos says "the fate of illegals is inextricably tied to the treatment of the lawful Mexican-American. Increasingly the recent phenomenon is to recognize this interrelationship." He says that only Mexicans, legal or otherwise, are asked by Texas school officials to prove their status.