in the public eye, what you say matters more.
The more people you speak to and the more people that listen means more thoughts that are generated from what you say. Offensive things said, such as racist comments, are held at a higher standard when more people know about it. It becomes a larger issue because you have so many thoughts coming your way about what was said. The more publicity it gains, the more of a problem it becomes.
Within peoples' thoughts are a type of stigma. Anything that might be slightly discriminatory is thought to define a person as a racist. People don't factor in the idea that not everyone means what they say because they are always defendant against what could be considered racism.
When people are stuck on who is and isn't racist, any discriminatory comment will cause those thoughts to jump to "he/she is racist". You can be defined by one little comment, and that's it. I think racism affects us by making our thoughts more definitive when it comes to a prejudicial remark. This in turn makes for a more hostile environment. You worry about what people will think after you made that comment, and you're cautious about what you say. Racism confines us a little more than we already are.