Here's the puzzle. Busing seems to be on its deathbed, but the public is actually less hostile to it than it once was. When asked by pollsters whether they favored busing for purposes of racial integration or the retention of neighborhood schools, whites opposed busing by an 87 to 13 margin in 1972. But by 1996 the split was 33/67. On the other hand, perhaps this doesn't mean much. White families had headed for the suburbs, and once you're safe in, say, Newton, your ire at Judge Garrity may soften. Busing is someone else's problem.
You assume black opinion has changed. Not so. Busing never had overwhelming support. In 1972, for example, African Americans backed busing by a 55/45 margin; in 1996 the split was 59/41, a difference too small to be statistically significant.
All this is a bit baffling, because--as you say--it is hard to imagine another example of a social policy that has been more of a flop. As the Boston case demonstrates so clearly, it is impossible for federal judges to engineer the "correct" racial balance. Judge Garrity did not manage to get all of Boston's African American schoolchildren into white-majority schools. He only succeeded in driving the city's middle class, black as well as white, out of the Boston public schools altogether. The average black child in the city's schools today actually has fewer white classmates, despite the massive and extremely costly busing scheme, than he or she did at the time at which Judge Garrity ruled that the system was segregated! There aren't enough white pupils left for meaningful integration. Pretty much the same shift occurred in Denver--a precipitous decline in public school enrollments and the quick disappearance of the white-majority schools of prebusing days.
Worse yet, it is now clear that getting the racial mix right seems to have no observable educational benefit. Despite white flight, busing did increase racial mixing in the short run, but the mixing didn't do anything much to improve to the educational performance of the African American students who were supposed to be its beneficiaries. Ten years after the massive and massively expensive San Francisco desegregation scheme went into effect, a committee appointed to review the results found to its dismay that black and Hispanic students did not display "even modest" improvements in their test scores.
The policy hasn't worked; white opposition is down and blacks are still on board. And yet, you're right. The ground is shifting. How come?