IT IS TOO BAD that President Carter's nomination of Judge James E. Sheffield to the federal bench is caught up in argument over Virginia's meritocracy. Judge Sheffield, the first black nominated for high judicial office in Virginia since Reconstruction, deserves better than that. His nomination should be evaluated by the Senate on the basis of his qualifications, not as part of a power struggle between the president and Sen. Harry F. Byrd Jr.

The facts on which that struggle is based are not in dispute. The interpretation is Sen. Byrd, at the president's suggestion, set up a commission to nominate candidates to fill four new judgeships. The panel nominated only white males. Besieged by complaints that a state that is 19 percent black and more than 50 percent female ought to be able to produce one non-white-male judicial candidate, the administration asked Sen. Byrd to try again. He refused, and the president has now nominated three white men from the panel's list and one black man suggested by other groups.

To Sen. Byrd, this is a "quota system" that contradicts the idea of merit selection of judges, an idea pushed vigorously in the past by the Carter administration. To the administration and those who persuaded the president to look beyond Sen. Byrd's list, this is simply a demonstration that extraordinary steps must be taken in some states to break the pattern of white males' exercising exclusive control over the levers of power.

In Virginia, the traditional sources of judicial candidates -- the places a commission would be likely to look -- are remarkably barren of blacks and women. Judge Sheffield is one of only two blacks to have served on a Virginia court of record in this century. No woman has ever served. Neither a black nor a woman has held an appellate judgeship, a statewide elective office or a federal elective job in the last 100 years. There are few blacks or women in the senior ranks of the state's leading law firms. There are only a handful in the state legislature.

In that environment, it is not surprising that Sen. Byrd's commission came up with the names of only white males. Nor is it surprising that the administration, with its commitment to put blacks and women on the federal bench, asked that the list be reopened. That was not a matter of turning away from the best qualified judicial candidates in the state. No list ever achieves perfection; the line between those who do and don't make the list is sometimes impossible to perceive. It was a question, instead, of wondering if there were not, somewhere among the state's five million people, one black or female lawyer whose qualification to be a trial judge were roughly comparable to those of the favored few.Judge Sheffield, after all, is the only one of the four nominated who has been a trial judge.

This is no "quota" system or "system" of any other kind. Virginia's black population has been excluded so systematically and thoroughly and unfairly from the state's meritocracy in the past that, if any among it now qualify for a federal judgeship, he or she has a very strong claim on the presidential nod. The Senate's decision on this nomination should not turn on Sen. Byrd's stubborn commitment to only those nominees on his commission's list.