Virginia's most powerful black political group today refused to endorse the Democratic candidate for attorney general despite pleas from Democratic leaders that a failure to endorse the entire statewide ticket would injure the party's chances in the fall.

The Crusade for Voters overwhelmingly backed Democrats Henry E. Howell for governor and Charles S. Robb for lieutenant governor, as expected. Republican J. Marshall Coleman won the group's endorsement for attorney general by a vote of 185 to 86.

The best-attended meeting in the Crusade's history was closed to the public as Richmond Mayor Henry Marsh, political activist Moses Riddick and AFL-CIO leader Earl Davis urged the group to support State Del. Edward E. Lane, the conservative Democratic candidate for attorney general.

Lane supporters argued, both before and during the Crusade meeting in the Hotel Jefferson that a failure to endorse Lane would damage Howell's chances of getting elected. But Coleman supporters won by the day by reiterating the Republican's complaints about Lane's record as a supporter of the state's plan of massive resistance to school desegregation in the 1960s.

Raymond Boone, editor of Richmond Afro-American, spoke for Coleman, "We must reward our friends and punish our enemies," he said. "Massive resister Ed Lane is not our friend now and he never has been. He is a longtime enemy of our dreams and aspirations and should be treated as such . . . What chance do you think any black person will have to get a sympathetic ear once Lane is home free?"

Speaking for Lane, Marsh said, "The President is asking and Walter Mondale is asking and Henry Howell is asking you to give him his (entire Democratic) ticket."

The Crusade claims to influence as many as 150,000 of the state's estimated 250,000 black voters, and the mood of the crowd was evident from the start. "Boos" could be heard emanating from the hall at different points, including following several mentions of Lane's name.

After the vote Marsh, who had himself been booed, said that he thought the Coleman endorsement would make it "more diificult for Henry Howell because it will polarize (voters) along racial lines. More conservatives will now be inspired to get out of Lane and while they're out there, they will vote for (John N.) Dalton," Howell's Republican opponent.

Marsh blamed the vote on the editor of the Afro-American, who he said had "worked people uo into a frenzy." The Rev. J. Henry Scott of Staunton and Charles Mangrum of Lynchburg also spoke for Coleman.

In the past week, the Afro-American printed a letter from State Sen. L. Douglas Wilder, a Lane supporter, asking Lane to apologize for his support of massive resistance. It also has printed several articles about the conflict, letter signed by Boone attacking Lane's record, and in today's edition, an editorial supporting Coleman.

Lane, who has been speaking to black groups in different jparts of the state, says that he now believes that massive resistance was "morally wrong," but has so far refused to apologize for his support of it.. he commonly likens his change of view to a change in "the times," and draws an analogy with such social trends as the advent of liquor by the drink and men and women living together without being married.

Sen. Wilder, who is the highest ranking black elected official in the state, did not attend today's meeting because he had a prior commitment to attend a legislative study commission meeting in Charlottesville.

There were reports during today's meeting that invitations, which are required for members to attend, had been duplicated to swell the ranks of voters. Thornton said that as a result of those reports, everyone, including those with temporary, $2 visitor's passes, was allowed to vote.

The Crusade's vote to endorse Howell was so lopsided that it was not counted, and Robb was unanimously endorsed because no one appeared to speak on behalf of his opponent, State. Sen. A. Joe Canada.

The Crusade's endorsement is not the only significant indication of black support in the state. There are congressional district black caucuses in several districts, for example, and in the Tidewater area the Golden Rod ballot packs a considerable wallop. The Golden Rod does not customarily make its decision until shortly before the election, and its endorsement is decided by a group of about 30 leaders.

This is not the first time the Crusade, which bills itself as a nonpartisan group, has endorsed a split ticket. It endorsed Republican Gov. Linwood A. Holton along with Democrats Andrew P. Miller and J. Sargeant Reynolds in 1969.

The group also endorsed Gov. Mills E. Godwin, a supporter of massive resistance, in 1965. However, as a Crusade member who attended a Seventh District black caucus meeting in Culpeper last night put it, "I think we need to take off the kid gloves."

Howell's campaign manager, William Rosendahl, said he did not view the Coleman endorsement as a potential handicap for Howell. "They voted for Henry unanimously," he said. "We're grateful and honored that they endorsed him." Rosendahl said that there are numerous other black groups in the state who have not yet decided which candidate to support and that thinking the Crusade's endorsement is a "true reflection of the overall black community is inaccurate.