THE POLITICS of the Bork nomination come down to the politics of gratitude with at least four new southern Democratic senators.

Without the black vote, Richard C. Shelby of Alabama, Wyche Fowler Jr. of Georgia, John B. Breaux of Louisiana and Terry Sanford of North Carolina would not be sitting in the Senate today. In every case, the loss of white voters was offset by a turnout of blacks.

That is why they agonize over the choice. White voters could be alienated by what they might see as a bowing to "special interests", by which is meant the pro-choice, anti-school-prayer groups that have been mobilized against Bork. On the other hand, they feel a certain sense of obligation to the people who rescued them from defeat.

Their victory, and their dilemma, arise out of the Voting Rights Act of 1965, one of many civil-rights measures opposed by Robert Bork, who saw no harm in the poll-tax because it was so small.

"The White House took all the southern votes for Bork for granted," said a southerner. "In the case of the class of '86, they could be wrong."

The White House has been madeaware of southern discomfort over Bork. It adds to their unease about the confirmation.

Breaux, who was the target of a vicious Republican scheme called "Ballot Integrity Program", whereby hard-breathing activists sought to sweep off the registration rolls the names of blacks who had failed to vote for Ronald Reagan. The plot was discovered, and nationwide attention was directed on the race. Breaux lost the white vote to his Republican rival, W. Henson Moore, but came home with 90 percent of the blacks.

"I'm finding that the opposition to Bork is much more intense than the support," he says.

His mail and calls are running 12 to one in favor of Bork but they are "generated" and from out of state. The pro-Bork mail consists of printed forms with names filled in. The antis write individual letters.

Sen. Howell Heflin of Alabama, a Democratic member of the Senate Judiciary Committee who once referred to Bork as "weird," will give no hint of how he intends to vote. He has wondered out loud what kind of a justice Bork would be. He must face the voters in 1990 and may have difficulty explaining his vote either way.

The reason for the depth and strength of the opposition was explained with great elegance and eloquence by black political stars Barbara Jordan and Andrew Young, who testified last week.

For them it is quite simple. They would not be where they are today if Bork's published views -- some of which he has repudiated -- had prevailed.

"I would right now be running my 11th unsuccessful race for the Texas House of Representatives," she declared with her awesome diction and in her chiming, cavernous voice.

The Supreme Court gave her her chance. Because of the one-man, one-vote decisions, she was finally elected to the state legislature and eventually to the House of Representatives, where, as a member of the Nixon impeachment committee, she sat in judgment on an erring president. She is now a professor of law at the University of Texas.

Andrew Young, as a poor young preacher, marched and sang at the side of Martin Luther King. He told the senators that if Bork's views on First Amendment rights had been in effect, King would not have been able to lead the great campaign for civil rights. "To think that we would not have been able to give the kind of aggressive non-violent leadership during that period is frightening."

In those days, he said, the Supreme Court was "the voice of God" to struggling blacks. Bork on the bench would mean a Supreme Court "that doesn't understand the passion and anguish of people whose rights are being denied."

Young's life was transformed by the court and the Voting Rights Act. He was elected to Congress and became Jimmy Carter's ambassador to the United Nations. He is now the Mayor of Atlanta, a booming city that is "too busy to hate."

Bork's allies try to point out that Bork the writer should be separated from Bork the judge. He has abandoned his old theories, they say. On the bench, he never rode them. But to blacks, he is indelibly identified as a heartless nay-sayer who coldly bade them to repair to their state legislatures in pursuit of rights that are not specifically described in the Constitution.

The southerners hope they will be spared a yes-or-no vote on Bork. A filibuster, by forcing withdrawl of the nomination, might provide the answer. A filibuster could be sustained with the southerners' help. It is a fine old southern tradition to vote against cloture, the closing-off of debate.

A filibuster could be a way out acceptable all around, showing blacks that the southern Democrats understand -- and showing whites that they are preserving the southern way of life.

Mary McGrory is a Washington Post columnist.