THE MEMORIES are still vivid. As I marched across the Edmund Pettus Bridge in Selma, I could see nothing but a sea of blue-uniform-wearing Alabama state troopers silently waiting on the other side. But we were determined to dramatize the need for voting rights.

What followed was a confrontation that became known as "Bloody Sunday." The scenes of helpless marchers being clubbed on national television shocked the nation. Our sacrifice moved Lyndon Johnson into pushing for passage of the Voting Rights Act of 1965.

I met with Johnson at the White House on the day he signed the Act. The road from the Edmund Pettus Bridge had been difficult, but on that day, Aug. 6, 1965, our nation had completed an important leg of an ongoing journey.

In the 25 years since, U.S. politics have undergone a remarkable transformation. The registration of millions of black and Hispanic voters made it possible for thousands of minorities to win office at local and state levels. In 1965, there were 500 black elected officials across the country; fewer than 100 were in the South. By early this year, the total had increased to 7,370, 4,955 of whom were in the South.

In national politics, minority voters provided the margin necessary for Jimmy Carter to win the presidency -- and made it possible for Jesse Jackson to make a significant showing in the 1988 contest. Since the 1960s, there have been dramatic gains in the number of minorities receiving appointments to high-level federal executive, judiciary and national party positions.

Today, the changes brought on by the 1965 law have also cleared the way for one of the most promising developments unfolding in American politics: minority-led, "coalition politics." The victories last year of Virginia Gov. L. Douglas Wilder, New York Mayor David Dinkins and Seattle Mayor Norman Rice stand as clear examples of minority candidates putting together biracial coalitions.

These elections signal a new level of maturation in American politics. They demonstrate the willingness of white voters to set aside racial differences, and they reflect the fact that many minorities have gained the broad political experience and skills to make them solid candidates for major offices.

These successes come at a time when the U.S. political system most needs to confront racial divisiveness. The election of David Duke to the Louisiana State Legislature suggests a resurgence of racism or racial resentment among conservative white voters that could spread to other parts of the country. During recent years, racial tension has simmered high in several U.S. cities. In 1988, Republicans gave convicted murderer Willie Horton a starring role in a presidential campaign advertisement shamelessly designed to scare white voters.

The development of minority-led coalition politics offers a contrast to racial politics as well as concrete opportunities for the two major political parties.

Democrats will be facing some of their toughest tests in the years ahead. Fighting the loss of traditional constituencies (Southern white males, working- and lower-middle class white ethnic voters), they are struggling to keep the party's broad, biracial base intact. There has been resistance from some Democrats, particularly in the South, in accepting minorities as nominees for political office.

But if minority candidates can attract voters on issues rather than race, the national Democratic party can more easily maintain the coalitions it has depended on since the New Deal. This year, Andrew Young in the Georgia governor's race and Harvey Gantt in the North Carolina Senate race have sought to build viable biracial coalitions.

As Democrats seek to redefine their mission, party leaders must remain true to the long-held commitment to social justice and equal rights. The party cannot risk losing its most loyal constituency by turning its back on that legacy.

And the more successful the Democrats become in accommodating minority-led coalition building, the more pressure will build upon the GOP to restyle its appeal. Republicans have won the presidency the last three times with less than 15 percent of the black vote, but there is a growing recognition that minority voter participation has begun to hurt GOP candidates in local and state races. Not surprisingly, they have begun programs to lure black voters into the GOP fold.

One GOP tactic -- working with black Democrats to create majority-black congressional districts during the 1992 reapportionment -- is viewed with concern by many Democrats, black and white. A particular worry is that such overtures to black Democrats will threaten Democratic biracial coalitions.

No one, though, should fear the prospect of minority-led biracial and multi-racial coalitions. The prospect is a natural development of American politics and society, which have come a long way since "Bloody Sunday." We should embrace the consequences of the Voting Rights Act. Its passage was a triumph of the American political system.

John Lewis, former head of the Student Nonviolent Coordinating Committee, is a Georgia Democratic congressman.