For four days last week, the Senate Judiciary Committee hearing room was an extraordinary showcase of the new South, though a touch of the old intruded at times.

There in the front row sat U.W. Clemon and Fred D. Gray, President Carter's nominees to be the first black federal judges from Alabama. Both are heroes of the civil rights movement and they brought with them an impressive list of supporters that demonstrated the increased political clout of blacks in the South.

Sens. Howell T. Heflin (D) and Donald W. Stewart (D), their home-state sponsors, sat through much of the 12-hour sessions, usually joined only by Sen. Max Baucus (D-Mont.), a freshmen chairing the hearings in the absence of more senior members of the committee.

The hearings on Clemon and Gray are just the latest in the unprecedented number of nominations of members of minorities to coveted seats on the federal judiciary by the Carter administration.

According to figures compiled by the Justice Department, Carter has appointed 38 black judges, double the number who were on the federal bench when he entered office.

In fact, about a third of the record 260 judges Carter has nominated during his term in office have been blacks, women or Hispanics. There were only five women and five Hispanic federal judges when Carter was inaugurated in 1977. Since then he has appointed 39 women and 14 Hispanics.

President Nixon appointed 238 judges from 1969 to 1974 and President Franklin D. Roosevelt filled 211 judgeships in his four terms. Carter's numbers are so high because of the 152 new judgeships created by Congress in late 1978.

But there was an undercurrent at the Clemon-Gray hearings that also reminded observers of the old South, where color was -- and apparently still is at times -- a much deeper issue than a way to count increasing equality in justice.

There was testimony at the hearing about how a state trooper once dragged Clemon from his car and pointed a gun at his head after a speeding violation. And a white lawyer, in Tuskeegee, in a touching witness, admitted he had once hated to shake hands or sit down with Fred Gray because he was black.

The same overtones were clear from the opposite perspective too, as witnesses such as Clarence Mitchell from the Leadership Conference on Civil Rights implied that the American Bar Association had racist motives in questioning the qualification of the two black nominees.

For the first time the ABA was opposing the nomination of black candidates and Robert D. Raven, of San Francisco, head of the ABA investigating committee, was visibly upset by racism charge and committee attacks on the bar association's work.

Late Tuesday evening after a long day he said he was shocked at the Senate and accused the committee of trying to kill the messenger of bad news. "Do you think we want to find black judges unqualified? Do you think we're fools?" he said.

Raven said the committee eventually will have to recognize that some minority-sponsored candidate is not qualified to be a judge. He added in a later phone interview that he didn't expect in this election year that the Senate will go along with the ABA recommendation. "But you can't face yourself if you don't call them as you see them," he said.

Senate aides and several observers at the hearings felt the ABA case against the two nominees was damaged by the same carelessness of which they accuse Clemon and Gray.

The ABA alleged Clemon lied when he said on an ABA questionnaire that he didn't have a tax lien. Clemon said he was just sloppy. And the ABA raised serious questions about Gray's competence in representing the city of Tuskeegee on two bond issues that resulted in the loss of hundreds of thousands of dollars to investors in the early 1970s. Gray is scheduled to answer the charges Wednesday.

The Clemon-Gray situation is noteworthy too because of the political overtones surrounding their nomination by the president. Their names were among 17 candidates for five judgeships forwarded to Heflin and Stewart from a state nominating commission last spring. They were picked by the senators and sent on to the Justice Department and the White House, where the recommendations sat for months.

It was only this January, after an extraordinary personal trip to Alabama by Attorney General Benjamin R. Civilett, that the names of Gray and Clemon were forwarded to the Senate.

Early this year, backers of Sen. Edward M. Kennedy (D-Mass.), chairman of the Judiciary Committee and Carter's challenger for the Democratic presidential nomination, charged that the Carter camp was trading judgeships for votes in the March 11 Alabama primary.

Birmingham Mayor Richard Arrington, a Clemon supporter, sent word to the White House that he had to know the fate of Clemon's nomination before the Jan. 15 filing date for Carter delegates in the primary. On Jan. 4, Civiletti made an unannounced trip to Alabama and questioned both candidates. On Jan. 10, the president forwarded the nominations and then Arrington signed up for Carter.

Other black lawyers in Alabama were considered for the judgeships, but they didn't have the policial backing of Clemon and Gray. "The black leadership in Alabama wanted their blacks, not someone else's, one Justice official said.

The same has held true in other states. In Georgia, for instance, a young black attorney was passed over for a judgeship in favor of an older man who had "paid his dues in the movement," according to one participant in the selection process.

Freshman Sen. Baucus will play a key role in the outcome of the Clemon-Gray hearings because absent committee members by tradition lean heavily on the recommendation of the colleague who attended the most. That was the case earlier this year when the committee backed the conclusion of Sen. Patrick J. Leahy (D-Vt.) that Charles Winberry, a longtime supporter of Sen. Robert Morgan (D-N.C.), wasn't fit to be a judge. The rejection was the Senate's first in more than 40 years.

The entie issue may be moot, however, because Republican members of the committee led by ranking minority member Strom Thurmond of South Carolina seem ready now to stall further processing of judgeships altogether in hopes of saving them for a possible Republican president.