COLUMN LEFT : A Thomas Idea Could Energize Liberal Engine : His expansive view of one clause in the Bill of Rights may work against conservatives.

Liberals prepared to take the long view of the Supreme Court’s development of constitutional protection for individual rights can find one bright side to the nomination of Clarence Thomas. To be sure, if Judge Thomas is confirmed, his rulings will predictably continue the court’s conservative trend. But that would be true of anyone on the Administration’s short list of candidates. What makes Thomas different is that he will try to take the court’s interpretation of the Bill of Rights in a new direction, one that in the long run may hold more promise for liberals than for conservatives.

For more than 30 years, the modus operandi of liberal jurists has been to give expansive interpretations to two vague, open-ended clauses of the 14th Amendment that guarantee “due process” and “equal protection of the laws.” The language of these clauses is so broad that they invite use by judges seeking new ways to justify expanding individual rights. Judges appointed by Presidents Reagan and Bush have shut down this method of expanding the scope of individual rights, largely by tying the clauses to the meanings they supposedly had when drafted in 1866.

Having finally curtailed new developments under these clauses, the last thing traditional conservatives want to see is a push to open up another equally vague provision of the Constitution that could be used by those who think it must change with the times.

That just such a move is required is a central tenet of Thomas’ jurisprudence. He has made plain in his writings that he believes a little-noticed clause of the Bill of Rights that prohibits states from violating the “privileges or immunities” of American citizens is the centerpiece of the Constitution’s protection of individual rights. To say that this view is unfashionable is an understatement: The potential importance of a re-energized privileges or immunities clause should not be underestimated.

A great many of the Warren Court’s opinions expanding individual rights under due process and equal protection could just as easily have been decided under the privileges or immunities clause. A woman’s decision on whether to abort a fetus could as readily be called a privilege of citizenship as a right of privacy, and Thomas himself has written that Brown vs. Board of Education, the great school desegregation case, should have been based on the clause.

Moreover, the development of the privileges or immunities clause would be hard to contain. Those who drafted it never provided a list of privileges or immunities nor a means whereby they might be identified. A more inviting tool for a liberal jurist looking for a source of new individual rights is difficult to imagine.

Indeed, it is precisely this malleability--the clause’s ability to take on the meanings that an interpreter wants to ascribe to it--that has attracted Thomas.

He has an old-fashioned belief in “natural law.” Thomas has written, and his testimony before the Senate committee confirms, that he believes that there is a set of moral rights and principles that existed before the Constitution and forms its “higher-law background.” Thomas insists that these natural rights were “given to man by his Creator, and did not simply come from a piece of paper.” Looking for a place to locate these God-given natural rights in the Constitution so that he can use them to adjudicate constitutional cases, Thomas found a receptive spot, the privileges or immunities clause.

Liberals, of course, cannot ignore the damage that a Justice Thomas would likely do to their vision of a Constitution that protects a broad range of individual rights, like abortion and equality through affirmative action. Thomas’ claim of a divine source for individual rights must be profoundly troubling to anyone who believes in the separation of church and state.

Moreover, Thomas’ writings show that he has a very narrow conception of what rights we have, and that they consist almost entirely of negative rights to be let alone rather than positive rights to government assistance.

This will distress those who believe that the Warren Court’s expansion of rights made the United States a better society. Nevertheless, if a Justice Thomas could persuade the court to reinvigorate the privileges or immunities clause, it could eventually, in liberal hands, prove a powerful engine for the development of new individual rights.

After all, J. Harvie Wilkinson, a Reagan appointee to the federal bench, wrote that the clause “holds special hazards” for conservatives and encouraged his fellow judges to leave it dormant, rather than “engaging in a disruptive roll of the dice.”