Washington — Extension of the 1965 Voting Rights Act, an issue skirted by the President in his NAACP speech this week, poses tough questions for the Reagan White House. To blacks, the act represents an essential bulwark against discrimination. But in the view of many white Southerners its extension would perpetuate a stigma placed on their region during the Johnson era's attack on segregation in the South. Mr. Reagan's delicate task is to allay blacks' concerns that they will be economically and politically victimized by his administration, while assuring white Southerners that the stigma will be lifted.
The act is not slated to expire until August 1982. But already Democrats on Capitol Hill and civil-rights and advocates are pushing for congressional action on its extension before the August recess.
The Reagan administraton wants to delay a prolonged wrangle over any issue -- domestic or foreign -- until it gets its economic package approved.
To gain time, President Reagan has asked in a letter that Attorney General William French Smith take until Oct. 1 to review the voting rights issue and recommend a White House position. The act requires states with a record of racial discrimination to receive clearance from the Justice Department before changing local voting law.
A possible solution for the White House would be to support renewal of the act, but insist that it apply to all parts of the country, as some Southern Republicans have urged.
Whatever it does, the Reagan administration must travel a tricky path that risks offending blacks -- and white civil-rights advocates -- on the one hand, and Southern whites on the other. The latter group is crucial to the conservative Democrat-GOP coalition now backing the Reagan economic program.
Common Cause, the public interest lobby, supports a full 10-year extension of the act so that it can apply to the 1990 voting district reapportionment.
"It's a real priority issue in the Congress for us," says Ann McBride, Common Cause legislative director. "Racial gerrymandering has become one of the new techniques for voter discrimination, now that the more blatant forms like literacy tests have been outlawed."
"The idea of applying the act nationwide is a strategy to kill it, to make it administratively ineffective," she says. The act already enables new districts outside the South to be brought under the "preclearance" requirements.
The Voting Rights Act has had a profound impact on minority participation in elections, experts agree.
"Of all the pieces of civil-rights legislation, it was the most effective," says Austin Ranney, director of political process studies for the American Enterprise Institute.
"Its goal was to level all of the barriers that existed, primarily in the Southern states, where there had historically been barriers against black registration and black voting," Mr. Ranney says. Black registration and voting levels shot up by 300-to-400 percent in a few years.
In Mississippi, black registration was less than 7 percent in 1965, then jumped to 67 percent by 1976. There were fewer than 100 black elected officials in the South in 1965. By 1980 there were almost 3,000.
"Has the act largely done its work?" Ranney asks. "Yes, in real terms. No, in symbolic terms."
The act has largely done its practical work , in Ranney's view. Blacks are either a significant or the dominant force in many areas where they did not vote at all before passage of the act. "The chances, if the act were to lapse, that people would go back to the old practices and keep black voters from voting, are really nil," Ranney says.
"On the other hand, the presence of the act -- the gun behind the door of federal presence to intervene in case of a relapse -- is not only a memory of a great victory for blacks, but it's a psychological reassurance that they regard as important," Ranney says.
Surveys by Data Black, a black-owned opinion research firm headed by Dr. Kenneth Clark, reveal the Reagan administration already has some shoring up to do in the black community.
Blacks do not agree with many of the positions taken by Reagan, most recently in his June 29 speech to the National Association for the Advancement of Colored People convention in Denver. By more than 2 to 1, blacks reject the statement that federal welfare programs harm them by encourag ing dependency on government , the Data Black surveys show.