He called the residents of Boston "racists." He called Pirates fans racist because they liked Andy Van Slyke (a fan-friendly extrovert and great center fielder) more than him. He's made remarks about how important it was for him to pass Ruth because Ruth was white. He went on steroids because "white boy" Mark McGwire was getting so much attention. I can recall those off the top of my head, I'm sure there are lots of others including many unreported ones.