A senior Virginia Democratic legislator, pointing to more than a decade of election defeats, today called for sweeping changes in the way his party nominates its candidates for statewide office, a proposal that immediately opened an intense, racially tinged debate.

Senate Majority Leader Hunter B. Andrews, a party moderate from Hampton, opened the issue by urging that elected Democrats be made delegates to nominating conventions. That step automatically would boost the number of moderates and conservatives at conventions that frequently have been dominated by liberals, union members and blacks.

The American Civil Liberties Union, which has monitored political rights in the state, quickly denounced the move as an attempt to limit the participation of blacks in the Democratic Party. Several black Democratic legislators also expressed reservations.

"The limiting aspect of it bothers me," said State Sen. L. Douglas Wilder of Richmond, who has announced he will seek the party's nomination for lieutenant governor next year. "It may or may not be motivated by the massive influx of blacks in support of the Jesse Jackson presidential campaign this year," said state Del. William P. Robinson (D-Norfolk).

Richard Taylor, a voting rights specialist for the Virginia chapter of the American Civil Liberties Union, said that the organization would complain to the Justice Department if the Democrats accept any proposal that results in a "regression" of party rights for minorities. The department monitors Virginia's election laws under the Voting Rights Act.

"We really feel that its unfortunate that the majority leader would find it necessary to take the leadership here in advancing a plan that without disguise and without qualification is designed to substantially reduce minority participation in the decision-making process . . ," Taylor said.

Andrews, who was known as an opponent of Virginia's "massive resistance" to public school desegregation when elected to the legislature in 1963, bristled at a reporter's suggestion his proposal might be interpreted as racially motiviated. "I deny it emphatically and if you interpret it that way, you are the racist, sir," he shot back.

The senator, who has said he is alarmed by the increasing number of Republican victories and the flight of white voters from the Democratic Party, suggested that the total number of convention delegates be limited and that the party abandon its current use of mass meetings to select convention delegates. Under his plan, elected Democrats would make up about half of a convention of 2,500 Democrats.

Robinson and Wilder both expressed concern the proposals may be used by others to block participation by blacks.

"We do have a problem based on the demographics of the recent elections . . . an exodus of the Southern white male," Robinson said today. "In a sense we blacks have been perceived as being too successful," Robinson said. "I'm concerned about the problem but there's a bit of hypocrisy in saying we want you but we don't want you too much."

Robinson said the party could revise its nominating process but warned of a major battle if it were used to unfairly dilute black strength.

The state party is to decide on its delegate selection process in January, although party officials said it also will be discussed during this weekend's meeting of the ruling state central committee. The nominating convention is scheduled for June 7 in Richmond.

Andrews urged Gov. Charles S. Robb, a leader in the national effort by Democratic moderates to gain control of the party, to host a summit of top state Democrats to consider changes "to make our party more representative of the viewpoint of a majority of Virginians."

Robb's press secretary, George M. Stoddart, said the Andrews proposal appeared similar to Robb's national proposals. He said the governor would study the idea when he returns to Richmond this week.

State Democratic Party Chairman Alan A. Diamonstein of Newport News disputed racial motives of any elected leaders.

"This is something we have been trying to do more and more on the local and national level, get elected officials involved," Diamonstein said. "It doesn't mean it has to be at the expense of any individuals."