Human nature says that there will always be at least a small amount of racism everywhere. It is a natural reaction. In more civilized societies, it is a natural trait that we work to overcome. In America, most white people have succeeded in doing just that, as we have seen by electing an African-American president.
In any presidential election with two white candidates, each would normally receive 40-60% of the vote. In the 2008 election, Obama got 57% of the vote, which indicates race had little to do with the election, at least as far as white voters go. But if you look at how people voted by race, you will notice that a whopping 94% of the black community voted for Obama, not the 40-60% you would expect if the black community were not voting by color alone.
Of course, that particular election can be attributed to the fact that it was the first time blacks could vote their color in a presidential election, so we can overlook it. But in a recent poll by the NYT, the same 94% of the black community says they will AGAIN vote for Obama, even though they are doing worse under his presidency - their income is down more than whites, and unemployment has risen much more than whites, and their educational opportunities have shrunk under Obama. This means they are voting color again, and not policy or performance.
In other words, there is, indeed, racism in America, but the vast majority is coming from the black community, not the white. And that contributes to the number of white people who are still racist. Though very few whites are racist today, many of those who still cling to racist views are doing so because they see and feel the abundance of racism coming from the black community. After all, it is difficult to like someone who hates you.