I think it is a proven fact that if you confront a person and call him a racist over his racist comment he made he will most likely deny it and depending on how threatened he feels about being called a racist he may go on the counter offensive and call the confronter racist.
You most likely are not going to get a confession and a miraculous turn around from the accused during a reelection campaign that would be political suicide. I'm dying to see how Trump plays out his hand on this one he might surprise all of us.