Christians should know better. I don't mean those who simply call themselves "Christians" but those who strive to live a Christian life based on the Bible principles. I'd like to point out that the Bible says in 1 John 1:5 God is light; in him there is no darkness at all.--Verse 9 says that Anyone who claims to be in the light but hates his brother is still in the darkness (not with God, not Christian). And verse 11 specifies that whoever hates his brother is in the darkness and walks around in the darkness; he does not know where he is going, because the darkness has blinded him. Finally, 1 John 3:15 go further in saying that anyone who hates his brother is a murderer, and you know that no murderer has eternal life in him.
It seems to me that one cannot claim to be a "Christian" and be racist at the same time. As Christians, we should definitely pray in reference to 1 John 1:11 that God opens people eyes so that they can see and understand what Christianity is all about.