I don't think anyone is disputing that some people will vote based on race. Some people will vote for a candidate for all sorts of arbitrary reasons, race being just one of them.
I was taking issue with the fact that you cannot say a specific person is voting for a specific candidate for reasons of race UNLESS they admit to such a thing (which many people would openly admit to). The fact that anyone would make such a claim (which requires insight into a person's interior motives) is at best presumptuous and at worst racist. The end.