A president's executive appointments can be removed as soon as he leaves the White House. But his judicial appointments live after him for years, for good or evil.

In this respect, Jimmy Carter has an opportunity to influence the course of justice as profoundly as did Richard Nixon, who left behind a Supreme Court titled toward his biases. Now Carter can fill 152 new federal judgeships, created by an act of Congress.

Along with replacements for those who die or retire during the Carter years, the new appointees will number fully one-third of all federal judges. Carter's choices will have a healthy, or devastating, effect on our judicial system well into the 21st century, because federal judges are appointed for life.

The Constitution does provide for one other means of removing a federal judge besides death or voluntary retirement; he can be impeached for "high crimes and misdemeanors." But it is almost as difficult to impeach a federal judge as it is to impeach a president.

A judge can be abusive, senile, autocratic, corrupt or otherwise unsuited to sit in judgment on American citizens and corporations. But unless and until his peccadiolloes can be elevated to the status of "high crimes and misdemeanors," the judge can continue to dispense his own peculiar brand of justice.

So the care with which the presidentially appointed selection committees separate the fit from the unfit becomes a matter of extreme importance. Even in ordinary circumstances, their job is tough enough, given the number of hopefuls they have to choose from. There are few lawyers who do not covet the prestige, salary, perquisites and lifetime security that appointment to the federal bench would bring.

Now, with 152 more positions to fill, the selection committees' task is a nightmare. There are those in the Congress, and in the judiciary itself, who fear the task is hopeless.

In the rush to judgment on the raft of eager candidates, the committees may not have time to catch a closet racist, an arbitrary hanging judge -- or, another Judge Willis Ritter.

Ritter was a rotund, silvery-haired man who ruled on the federal bench in Utah in a disgraceful manner. He became a legend in his own lifetime -- a legend that supplicants before the bar of justice were relieved to consign to history when he died last year.

The sad truth is that every character trait that made him an ambarrassment to the federal judiciary was brought out at his confirmation hearings in 1949, but he was appointed anyway. Such is the overriding influence of the selection committees that, even when they made an obvious mistake as in Ritter's case, Congress rarely reverses their choices.

We have seen still-secret FBI files and minutes of Ritter's confirmation hearings that illustrate the weaknesses of the appointment system. We hope this will give pause to members of Congress who may be tempted to accept the recommendations of the selection committees, without careful scrutiny.

It was all laid out for the Senate Judiciary Committee by a respected witness, H. Grant Ivins, who had worked with Ritter at the olf Office of Price Administration in World War II. Here's what he had to say about Ritter in 1919.

"[He is] not a fit candidate for judgeship . . . He treated property owners like criminals and lawbreakers, refusing to recognize their right honestly to differ with him . . . He was arbitrary, tyrannical and arrogant and abusive in the treatment of those who sought conferences with him . . . . His prejudices are so violent, his respect for others so lacking, his integrity so questionable as to make him unfit for calm objectivity and absolute honesty." Almost unnecessarily, Ivins added that Ritter "has a temper which is violent."

Other witnesses supported Ivins' assertions. One, a U.S. attorney who had crossed swords with Ritter in a court case, testified that after the trial Ritter "berated me, used profane language, charged me with persecuting honest businessmen [and said] he would see to it that I get canned."

Ritter's defense to the latter charge apparently disarmed the senators at his secret committee hearing.

"I expect I complained forcefully and I may have complained profanely," he acknowledged, "but it is quite in character that I might have done so."

Neither the witnesses' predictions of disaster nor Ritter's disingenuous confession of human frailty reached the public. The hearings were closed, the derogatory reports were filed away and Ritter became a federal judge.

As it turned out, though, the public wasn't long in finding out about the Ritter temperament. His violent temper, unjudicial badgering of witnesses and attorneys, arbitrary harassment of news reporters and other court visitors -- in short, his total lack of fitness for the job -- all became painfully clear.

His story is one the selection committees and the Senate Judiciary Committee should ponder long and hard.