The Virginia Crusade for Voters, the state's best known black political action group, yesterday endorsed Democratic U.S. Senate candidate Andrew P. Miller by a 57-33 vote of delegates meeting here.

The expected choice by the Crusade of Miller over his Republican rival, former Navy Secretary John W. Warner, gave the Democrat a sweep of three statewide organizations considered important to a Democratic victory. Miller was endorsed earlier last week by the state AFL-CIO Committee on Political Education and last month by the political action committee of the Virginia Education Association.

Miller's moderate-conservative stands on some issues when he was state attorney general and a candidate for the Democratic nomination for governor last year tempered the enthusiasm of the endorsements by all three groups. But Miller supporters yesterday read the results as heartening -- a coalescing of traditional Democratic voting blocs behind their candidate.

Miller was able to muster three of the state's most influential black political figures to speak on his behalf at the closed endorsement session -- Richmond Mayor Henry L. Marsh, Newport News Vice Mayor Jessie Rattley and the Rev. Curtis Harris, a former 4th Congressional District House of Representatives candidate from Hopewell.

Rattley, a long-time supporter of Miller's old Democratic Party foe, Henry E. Howell, reportedly moved many delegates by telling them, "Andy is a politician who listens and who can be trusted. He is no phony."

Howell, the populist champion of Virginia's black voters, labor unions and teachers, beat Miller in the divisive Democratic party primary for governor last year and Harris read yesterday's Crusade vote as a restoration of unity between Miller and Howell supporters.

"After this," he said, "I think the wounds of the Andy Miller-Henry Howell conflict are healed and the influence of the Crusade will be increased."

The Crusade vote was informally contested by Norvelle Robinson, a Republican and chairman of the Richmond chapter of the Crusade, who objected to the disqualification of 33 Warner voters who did not bring their letters of invitation to the meeting with them.

Dr. William S. Thornton, state Crusade chairman, ruled that possession of the letter was a requirement for voting. Thornton said 700 letters were mailed to Crusade members throughout the state, but most at the meeting agreed it was dominated by Richmond area residents.

Warner campaign aide Joel Harris said after the vote that the results "show that John Warner has broad support in the black community."

Miller and Warner spoke briefly to the delegates before they met in closed session. Miller cited his record as the "first attorney general to open the doors of that office to all people" and promised to include blacks on his senate staff. Neither of Virginia's senators. Independent Harry F. Byrd Jr. and Republican William L. Scott, has a black staff member.

Miller and Warner are running for the seat being vacated by Scott's retirement.

Before the meeting began, the candidates and their wives, Doris Miller and actress Elizabeth Taylor, moved among the delegates shaking hands.

Taylor apparently foresaw an adverse outcome during this exercise. As she shook hands, she turned to a campaign aide and said softly, "There are too many Miller badges here."