Ilya Somin emailed me this response to my post on the backlash to desegregation.  Reprinted with his permission.

As you know, I rarely disagree with you about immigration issues. But I think the backlash against desegregation was a much bigger deal than you suggest.

First, it’s worth noting that the first effort at desegregation during the 1860s and 70s created a big enough backlash that blacks were horribly oppressed for decades thereafter. It is debatable whether the federal government could have managed things better or could have broken the resistance if they tried harder. But it’s a sobering precedent, at the very least.

Second, during the 1950s and 60s, although desegregation was ultimately successful  there was considerable violence and extensive “massive resistance” of other kinds. Ultimately, the resistance failed because, among other things, the federal effort to break it commanded widespread support everywhere but among white southerners, and even a significant minority of them had lost faith in Jim Crow by the 50s. Had it been attempted earlier, when resistance was stronger and will to break it weaker, the result might well have been different. On balance, I think the effort to expand black rights during Reconstruction still did more good than harm, but the issue is debatable, and the experience with Jim Crow suggests it took a long time before public opinion evolved to  the point where a large-scale effort to break down Jim Crow could succeed.

The lessons for immigration policy are not exactly straightforward and unequivocal. If I had to compare the two, I would say that current public opinion on immigration is roughly where opinion on race relations was in the 1930s and 40s, or – perhaps even somewhat earlier than that. There is growing doubt about the justice of immigration restrictions, but as yet only a relatively small minority supports the complete dismantling of the segregation system (even though many more people are willing to countenance more moderate reforms).

Me again:

I agree on the backlash in the 1860s and 1870s, though we should think of that primarily as the backlash to abolition of slavery.  And the net positive value of that change seems clear-cut to me.

For desegregation in the 1950s and 1960s, though, resistance seems feeble indeed relative to the magnitude of the change.  Every murder listed here was tragic, but desegregation cost fewer lives than 1% of a tiny civil war.