DEMOCRATIC candidates for president have been knocked out in five of the last six elections. The usual explanations for the decline of Democrats' presidential fortunes include: New-Deal Democrats are dying off; the country has moved to the right; primaries give the advantage to liberal candidates.But another reason has received less attention. Since 1964, no Democratic presidential candidate has received a majority of white votes. In 1968, white working-class voters began to desert the Democratic Party in droves and have continued to this day. As Washington Post writer Thomas Edsall has written, before the passage of the 1964 Civil Rights Act and the 1965 Voting Rights Act, neither party was strongly identified with civil rights. After 1964, the Democratic Party, in the eyes of most voters, becam e the party of civil rights. In 1988, almost one-fourth of the Democratic presidential vote was cast by black voters. In the traditionally Democratic South, only one-third of white voters went for Michael Dukakis. Democrats used to win presidential elections by building a coalition of low- and moderate-income Americans. Research by Robert Weissberg of the University of Illinois shows that many low- and middle-income white voters have become estranged from the Democratic Party because of its stand on racial issues. Whether the issue is busing, affirmative action, or welfare, many white Democrats disagree with what they perceive as their party's "pro-black" stands on these issues. And Democrats most dissatisfied with their party's stand on racial issues are those most likely to vote for the Republican candidate. Thus the Democratic Party's dilemma: The party's presidential candidates are heavily dependent upon black votes. Yet Democratic candidates can't win without bringing disaffected low- and moderate-income white voters back into the fold. How can the Democratic Party build a coalition of low- and moderate-income voters of all races to compete with a Republican Party that uses racial themes to win the votes of disillusioned white Democrats? Unless Democrats confront the issue of race, they will go on losing presidential elections. More important, a weakened Democratic Party leaves social policy to a Republican Party that has little interest in representing low-income Americans. One answer lies with what University of Chicago sociologist William Julius Wilson calls race-neutral policies. Race-specific policies like affirmative action, maintains Wilson, not only have been politically disastrous for Democrats, but rarely help the neediest blacks. The Republican answer is to use affirmative action to attack all poverty programs. What Democrats can do is to offer policies like comprehensive health care, public school reform, and job training programs that apply to all Americans. Democratic support for race-specific policies has left it unable to represent the interests of moderate- and low-income voters. Such policies are inevitably divisive because they treat blacks as separate from other Americans. This has made it easy for Republicans to use race to divide Americans whose economic interests are the same, while doing little to help them. Americans will accept additional spending to improve public schools, job skills, and health care if they understand that the money will be spent fairly. The political reality today is that most Americans, including most white Democrats, see affirmative action policies as unfair. Democrats should discard such policies in favor of programs that target disadvantaged Americans as citizens and not as members of a protected group. If the Democrats don't do it, no one else will!