Washington ? If there is one constitutional principle that has animated and energized conservatives during the last five decades, it is the notion of judicial restraint. Philosophers and politicians of the right have lectured Americans repeatedly about the dangers of “legislating from the bench.”

This is no idle chatter. Many of us who may be skeptical of other tenets of conservative faith — the aversion to taxes, say, or the priority of national security over individual rights — respect and share the belief that the judicial branch with its unelected judges should not usurp the functions and prerogatives of those in the legislative branch who hold their seats by vote of the people.

This is a principle which has been given eloquent expression by the heroes of the conservative movement.

Take, for example, the words of President Ronald Reagan in a 1987 radio address explaining his nomination of Judge Robert Bork for the Supreme Court.

Reagan described Bork as “a man who would be faithful to the kind of judicial restraint envisioned by our Founding Fathers, a judiciary that was independent and strong, yes, but one whose power also would be confined within the boundaries of the Constitution and the laws of the land. … That’s why over the years both progressive and conservative judges have understood the importance of judicial restraint — the principle that says the highest exercise of judicial duty is to subordinate the judge’s private views to what the law permits or determines.

“But now,” Reagan continued, “liberal special interest groups seek to politicize the court system, to exercise a chilling effect on judges, to intimidate them into making decisions, not on the basis of the law or the merits of the case, but on the basis of a litmus test or a response to political pressure.”

Despite that warning, Judge Bork was rejected by the Senate — the starting point for the unseemly and dangerous pattern that saw a Republican Senate majority block many of President Bill Clinton’s judicial appointments and the current Democratic minority use the threat of filibusters to hold up a number of President Bush’s judges.

The fault here is not in the judiciary. The fault lies largely in the legislators, whose actions are heedless of the damage these bitter partisan controversies wreak on the independence of the judicial branch.

In a properly functioning system of representative government, with divided powers and an independent judiciary, judges are obligated to avoid legislating from the bench and the legislature should exercise great restraint in intervening in judicial proceedings.

That is a principle which has been grossly violated in the Terri Schiavo case. As a parent, I can certainly sympathize with the anguish of her mother and father and their desire to give her every possible chance to extend her life, meager as it is.

But for Congress to substitute its own opinion for the considered judgment of Florida courts that have invested hundreds of hours in weighing this tragic case is unconscionable in constitutional terms.

No one in the truncated congressional debate suggested that the Florida judges had been biased or negligent or anything but conscientious in weighing the conflicting claims of Schiavo’s parents and her husband, and in evaluating the medical evidence about the poor woman’s condition.

The majority simply did not like the result of the case, and decided to intervene. The shift of jurisdiction from the state courts to the federal courts violated yet another conservative principle, the respect for the autonomy and diversity of states in the federal system.

The Republicans implicitly acknowledged that this intervention was a violation of several of their avowed principles. Instead of writing legislation that would affect similar cases, they passed a bill for the relief of this one patient.

But principles are brittle, and every time one is violated, it is weakened. This is not the first time that Republican leaders such as Sen. Bill Frist and Rep. Tom DeLay have cast aside sound conservative principles and precedents in order to achieve a short-term political objective.

Principled conservatives should be calling them — and the president who cheered them on — to account. When Congress overrules a state court judge, it is hard to argue with a straight face that a Senate minority has no right to block a federal judge’s confirmation.

Restraint is a virtue for all involved.