Well, you see it the way I do. Trende’s point is that the shift was already underway when Civil Rights legislation was enacted, meaning that there was *already* a reason for them to shift parties in play prior to the MLK/CRA period.
So, the next question then is “how did Civil Rights affect that ongoing shift; did it accelerate the shift?” Answer is NO, NOT REALLY. There is SOME indication that there was a slight jump for the GOP at the time, but then the shift returned to its normal slope line. We can conclude from that that the CRA was not a major factor in the realignment of the South.
The point here is that the ongoing lefty mantra which states “After the CRA was signed, all the conservative racists moved from the Dem to the GOP” just doesn’t hold any water.