For better insights into his actual feelings, one should look at his actions in office. I believe you will find that he either presided over a great improvement of educational opportunities for South Carolina's Negro people, or the plans for same were adopted during his administration.
Finally, the mainstream press were already very liberal on the "Civil Rights" issues, at this time, and would have pounced all over such a slur. I just do not believe it happened. This is just a cheap shot at a very old man, who is no longer able to defend himself effectively.