NOW THEY'RE AFTER the Voting Rights Act, the "Big Daddy," the most effective piece of civil rights legislation Congress has ever enacted.

For 95 years, between the ratification of the 15th amendment to the Constitution and the Voting Rights Act of 1965, court litigation was impotent in combating tyranny against minorities. But now the conservatives want to turn back the clock by letting the act expire in August 1982. That would mean those with voting rights complaints once again would have to go to court to seek relief instead of having their complaint handled administratively.

We saw this savage thinking coming. We saw it in the Supreme Court's recent decision in the City of Mobile, Ala. v. Bolden case, which has created so much confusion about standards of evidence for proof of voting discrimination that some Democrats are trying to amend the voting act to clear it up.

In that case, a plurality of the court upheld Mobile's at-large system of lecting city commissioners -- which had resulted in no black ever being elected in a city that is 35 percent black. Blacks argued that the system, established in 1911 when they could not vote, froze blacks out of political representation and left their calls for better municipal sevices and more employment unheeled.

Justice Potter Stewart said for the court that discrimination can be shown only through proof that an action was undertaken "at least in part 'because of not merely' in spite of its adverse effects upon identifiable groups." In other words, we will not strike down a law that creates discrimination, unless we can prove that discrimination was what someone was after all along. So a black citizen's constitutional claim is nothing unless he can show some specific and intentional official discrimination against him. This eliminates the need for attacking the system; just attack the individual practitioner -- if you can document his subjective thinking.

". . . Racial powerlessness, poverty and unemployment," wrote Arthur S. Miller, George Washington University law professor emeritus, last week of the black condition, "are rationalized, by the court and others, as historical accidents or the products of a malign fate -- or even by blaming the victim."

That's why the opponents of the Voting Rights Act can say with a straight face: "It isn't needed anymore."

Isn't needed?

Today in Mississippi, you have to register twice to vote -- once with the county clerk to vote in state and county elections and once with the city clerk to vote in city elections. Those living in northern Sunflower County must drive 50 miles to the county seat in Indianola to register for state and county elections then drive 50 miles back to their home town to register for city elections. And you must register for the county election first. How many of us would or could drive 100 miles round trip to register to vote between the hours of 9 a.m. and 5 p.m. on weekdays?

Isn't needed?

Is it just coincidental that in Edgefield County, S.C., home of Strom Thurmond, chairman of the Senate Judiciary Committee who wants to rewrite the act, that not a single black person has been elected to county office in this century, even though the population was 70 percent black in 1970 and is 50 percent black today?

In 1964, the year before the act, 2.8 million blacks in 11 Southern states were registered to vote. Today, 4.2 million blacks are registered in those same states; Hispanic registration has increased by 30 percent nationwide and 44 percent in the Southwest. Millions of poor whites have been enfranchised by striking down literacy tests. That's what was behind Lyndon Johnson's calling it "one of the most monumental laws in the entire history of American freedom" when it was passed. The doors of opportunity were opened to thousands of black and brown men and women who were elected to office.

While minorities have made their influence felt politiclly in the past 15 years, it's unclear to what extent political participation has opened avenues of economic opportunity. That should be the challenge for the 1980s. That would be looking ahead.

No, the ballot is needed more than ever to elect officials who will use their power and influence to improve the economic conditions of average people.By tampering with the vote, the conservatives are striking at the heart of minority power and opportunity -- and courting social chaos in the process.

Regardless of their motives, we could live for a long time with the result of their actions.