Twenty-six years ago Daniel Patrick Moynihan, then a Labor Department official in the Johnson administration, reported that a crisis in the black family was creating a split between ''a stable middle-class group that is steadily growing stronger and more successful, and an increasingly disorganized and disadvantaged lower-class group.'' The conclusions were controversial at the time, but Census figures over the years document the family crisis. In 1965, over 70 percent of black families included a married couple; a new Census report shows that in 1990 married couples made up just half of all black families.
The consequences for raising children are obvious. Children with divorced or separated parents are twice as likely to live in poverty as those with two parents. For black married-couple families the 1989 median income was $30,650; for ''female householder'' black families it was $11,360.
The same Census report shows married-couple households for all racial and ethnic groups declining steadily from 87 percent in 1970 to 79 percent last year. The pressures of racism may explain why blacks are more vulnerable than other groups to family breakdown, but clearly the ''post-marital family,'' as Senator Moynihan has called it, increasingly affects all Americans.