The number of blacks elected to office in the United States rose from 6,056 to 6,424 in 1985, or a little more than 6 percent, but that figure is less than a cause for rejoicing at the Joint Center for Political Studies, the research group that compiled it. The center says blacks now constitute 11 percent of the country's population of voting age but still hold less than 1.5 percent of its elective offices.
In addition, the current rate of increase is only about one-third of what it was from 1970, when the center began keeping statistics, to 1976. ''Further growth in the number of black elective officials is needed,'' said Eddie N. Williams, the center president, ''and will depend on the ability of black candidates to appeal to nonblack electorates.''
In Mississippi, for instance, only five percent of eligible blacks were registered to vote in 1960.
The law's effects were wide and powerful. By 1968, nearly 60 percent of eligible African Americans were registered to vote in Mississippi, and other southern states showed similar improvement. Between 1965 and 1990, the number of black state legislators and members of Congress rose from two to 160.