Eddie N. Williams, president of Washington's Joint Center for Political Studies, has been pushing an idea that isn't on the agenda for the Congressional Black Caucus' 12th Annual Legislative Weekend conference, now in session here, but should be a sizzling topic of conversation nonetheless.

Williams believes there is potential for a powerful political alliance between blacks and white women. Eleanor Smeal, head of the National Organization for Women, agrees. "It could be a tremendous political power alliance for the '80s," she says. "The attack from the right wing is galvanizing what could be a very powerful force."

Indeed, both groups see windows of opportunity closing and their economic futures threatened. Both have been victims of Reagan Newspeak. (Newspeak is saying you support a program as you attack the principles upon which it rests): Both have heard Reagan and the right wing speak in favor of affirmative action, but against timetables and goals. Both have seen vital social programs dismantled by spending reductions rather than outright votes to abolish. Both have had to contend with Reagan's appointment of antiblack blacks and antiwomen women to high positions in his administration.

Eddie Williams's new alliance would not be entirely new. Black legislators overwhelmingly voted for the Equal Rights Amendment. The Black Caucus has an excellent record on women's issues. Conversely, the National Organization for Women backed the Voting Rights Bill and learned a practical reality in the battle over the ERA: The South lacks black legislators because blacks find it tougher to vote. Had there been more black legislators in the South, ERA could have passed easily.

To be sure, there are serious issues that divide blacks and women. White women made more progress in the corporate world through affirmative action than did black men or black women, leaving a feeling of distrust among some blacks. Some blacks also say that the women's movement is a middle-class, white movement and even Smeal's NOW lacks black women in positions of leadership. I've been among the women critical of NOW for these very reasons.

Smeal says her organization has made a real effort to put black women in the pipeline for potential leadership by instituting "preferential balloting" to guarantee that 30 percent of the members of its board are minority members. "We want minorities in leadership," she says emphatically.

Yet the threat from the right is so critical that blacks must put aside past points of difference and even their navel-gazing over the question of whether they're black first or female first on a future agenda. Now is the time for a practical political agenda: What issues unite blacks and women, and how can they be turned to common advantage? We can hope that Smeal speaks for the majority of women when she says, "Our common goals are so strong and there is now such an obvious common opponent and such a reactionary one that it helps you overlook the little differences to band together to fight."

Some well-known black women have long understood this. Coretta Scott King, Dorothy Height, head of the National Council of Negro Women, Eleanor Holmes Norton, former chairwoman of the Equal Employment Opportunity Commission, labor leader Addie Wyatt, and former Pennsylvania Secretary of State C. Delores Tucker joined the battle for ERA. Elizabeth Koontz is part of a shadow cabinet fighting administration attacks on equity in education.

But rank and file black women too often view the women's movement from a personal and emotional standpoint rather than from a political perspective. Personally, no black woman should feel she has to make a choice between race and sex. But politically, it's clear that stressing what divides instead of what unites is an old -- and effective -- divide-and-conquer strategy. Why not simply unite over common concerns of all women, such as equal pay for equal work?

Individually, each group has shown it can be a forceful minority. Together, blacks and women can become a powerful majority.