An important part of what is often called “the American dream” is the ability of successive generations to climb the economic ladder. With workers’ productivity rising decade by decade, that should be the reality for working-class families.

But a series of reports released this week by the Pew Charitable Trust’s Economic Mobility Project reveals a very different reality for Americans as a whole, and shines a spotlight on the growing disparities facing African American families in particular.

While two-thirds of today’s adults are generally better off than their parents, the studies found, the biggest gains have been at the top of the income scale, and the smallest at the bottom.

A third of Americans are now worse off economically than their parents. And income growth for the other two-thirds is strongly related to the increase in two-earner families as more women have entered the workforce.

Of special concern is the finding that while incomes of both Black and white families have risen, the gap is widening. In 1974, African Americans’ median incomes were 63 percent that of whites. In 2004 they had slipped to 58 percent.

In a separate survey by the Pew Research Center, two-thirds of African Americans said they faced prejudice when they applied for a job or tried to rent an apartment or buy a house. Only one-fifth of Black respondents felt things were better now for African Americans than they were five years ago.

When coupled with the pervasive racial and ethnic discrimination faced by Latinos, Asian Americans and Native Americans, and the “American nightmare” faced by many immigrant families, it is clear that inequalities have risen alarmingly during the decades of far-right domination.

The struggle for equality is a vital component of the broad movement to end the far right’s rule and shape new foreign and domestic policies. Affirmative action, trade union protections, workers’ rights, public responsibility for health care, and quality education for all will help to close the gap.

Only when no one is left behind, when progress includes everyone, can anyone climb confidently up that ladder toward “the American dream.”