The Congressional Black Caucus, perennially written off by some detractors as a powerless social club, has assumed a new prominence in the House, highlighted by the selection of two of its own as chairmen of key committees.

Rep. William H. Gray III (D-Pa.) became chairman of the House Budget Committee on Friday. His selection followed by a few months the ascension of Rep. Augustus F. Hawkins (D-Calif.) to chairman of the House Education and Labor Committee, succeeding Rep. Carl D. Perkins (D-Ky.), who had died in August.

Black Caucus members, most of them with relatively safe seats and few competing political ambitions, now head five of the 22 standing committees in the House.

Blacks also serve as chairmen of two of the five less-important select House committees and of several prominent subcommittees. They also hold high-ranking seats that put them only a political heartbeat or two away from the leadership of other influential House panels, including the Ways and Means Committee.

Overall, 20 House members are black -- one of every 22 House members but one of every four of its standing-committee chairmen.

Caucus members and others say this signals a "coming of age" of the black lawmakers, the advent of more sophisticated, insider politicking and a long-sought focus for the caucus.

It also offers the black legislators the opportunity to have a stronger imprint on House legislation and a chance -- collectively and individually -- to play fuller and more powerful roles in Capitol Hill politics.

However, some wonder about the effect of the new strains on the black representatives to resolve their sometimes conflicting roles as spokesmen for their racially and economically integrated districts, for the poor, for black Americans in general and now for diverse congressional panels.

"My guess is that in the Black Caucus in the next two to four years, as they move into positions of leadership and prominence, there's going to be a sort of identity crisis," said political scientist Norman J. Ornstein, resident scholar at the American Enterprise Institute.

"All of a sudden you can't as comfortably play the role of purist or conscience," Ornstein said. "You can't ignore the needs of people who don't agree with you as chairman or you won't be chairman very long."

Rep. Mickey Leland (D-Tex.), Black Caucus chairman, said the new reality is likely to be an important element in the success or failure of Gray as Budget Committee chairman. In most recent years, the caucus has focused much of its dissent on the budget and presented alternatives.

"We have to reorganize our game plan in terms of the budget," Leland said. "We have to look at it from the point that we have a sympathetic ear and we have to protect his credibility and his integrity . . . . We don't want Bill to be just a one-term chairman.

"He also can't be shackled to being a black representative. He has to be a universal representative of the Congress . . . . We can no longer be parochial."

"It's just an added responsibility," said Rep. Julian C. Dixon (D-Calif.), who preceded Leland as caucus chairman. "Bill Gray will have to reach a very delicate balance in trying to bring together a budget."

Dixon was chosen Friday to succeed another black, Rep. Louis Stokes (D-Ohio), as chairman of the Committee on Standards of Official Conduct, the House ethics committee. Stokes had served the maximum time on the committee.

Rep. Ronald V. Dellums (D-Calif.) is chairman of the District of Columbia Committee and of an Armed Services subcommittee. Rep. Parren J. Mitchell (D-Md.) heads the Small Business Committee. Leland is chairman of the Select Committee on Hunger, and Rep. Charles B. Rangel (D-N.Y.) heads the Select Committee on Narcotics Abuse and Control.

Rangel wields perhaps more power, however, as the third-ranking Democrat behind the chairman on the Ways and Means Committee, where he heads the oversight subcommittee. At 54, Rangel could be said to have a slight edge over those with more seniority -- Rep. Sam M. Gibbons (D-Fla.), 64, and Rep. J.J. Pickle (D-Tex.), 71 -- to succeed Rep. Dan Rostenkowski (D-Ill.), 57, as chairman.

Rangel said the lure of the chairmanship is one factor discouraging him from running for mayor of New York this year.

Mitchell and Del. Walter E. Fauntroy (D-D.C.) rank fourth and fifth, respectively, among Democrats on the Banking, Finance and Urban Affairs Committee. Reps. John Conyers Jr. (D-Mich.) and Cardiss Collins (D-Ill.) stand third and fourth on the Government Operations Committee. Conyers is fourth on the Judiciary Committee, and Rep. William L. Clay (D-Mo.) is second on the Post Office and Civil Service Committee. Fauntroy is next in line to head the District of Columbia Committee.

Gray and Dixon won chairmanships with some help from relatively recent House rules that provide for rotating chairmanships and memberships on some panels. The others have benefited in large part from longevity that observers say is common among black members of the House -- much as it once was among southern Democrats.

The late representative William L. Dawson (D-Ill.) began the flow of big-city black Democrats to Congress with his election in 1942. Thirty-two blacks have followed. Twenty still hold their posts.

Of the remainder, two died in office and, like Dawson, were succeeded by blacks; six resigned and in four instances were replaced by blacks; and four were defeated -- in all but one instance by blacks.

Dawson also was the first black chairman of a House committee, taking over the Committee on Expenditures and Executive Departments, which later became the Government Operations Committee, in 1949. He headed it until 1953, when the Republicans took control of the House for one term. Dawson resumed the chairmanship in 1955 and held it until his death in 1970.

Black Caucus members invoke the names of Dawson, the late representative Adam Clayton Powell (D-N.Y.), who was chairman of the Education and Labor Committee from 1961 to 1967, and former representative Charles C. Diggs Jr. (D-Mich.), chairman of the District Committee from 1973 to 1979, in their support for the seniority system.

Without that system, they contend, probably none of the three would have ascended to their posts; and lacking an ironclad seniority system now, blacks are less likely to become chairmen of additional committees.

"We don't really think that racism in this country has so diminished that given the opportunity to vote on individuals based on their experience and ability that we could overcome that without the assistance of the seniority system," Rangel said.

Gray also gave credit to the seniority system, but said credit also must go to other black leaders in Congress who showed that blacks could be consensus-builders. Besides, he said, now there's no need to stage independent protests. "These days, you don't have to hold up signs to demand to get into meetings," he said. "We convene the meetings."

Observers say it is ironic that Gray, in only his fourth term, has become virtually the most powerful black in the House. But they add that he won the chairmanship of the Budget Committee by exhibiting keen understanding and significant mastery of the political process in the House.

That indicates a new breed of black lawmaker that Ornstein describes as "more institutional players" than some of their predecessors and elders. "A fire-breathing radical would stand out in the group as an exception," Ornstein said.

Some Black Caucus members agree. But the fire-breathing was necessary, Rangel said, just to get seats on key committees. "Everything we were doing was just to break through," he said.

Added Leland, "We understand that in order to get our point across we don't have to jump up and down on the table or shoot off fireworks to get the attention of the leadership. We go in and negotiate."