Dood, I know it'* hard, but you got to ignore idiots like that.
I've learned that racism comes from ignorance, and some people like being stoopid. People are scared of what they are ignorant about.
The guy has probably never got to know a black guy or had a black guy for a friend in his whole pathetic sheltered life.
Like Mista T says, "Pity the fool.'"
I grew up a poor white farm boy from South Dakota, where the only blacks we ever saw were on Sanford and Son, (that dates me a little...) and my dad would always says prejudice things about blacks. Then I went to college in Kansas City, and I became friends with Ray, a black guy. He became the closest, best friend I've ever had in my life, except for my wife. Until Ray and I became friends, I never knew it was possible for me as a guy to have another guy for such a close friend. We were each other'* best man, and all that stuff.
The cool thing about it is, Ray would come home with me to South Dakota for vacations once in awhile, and my dad got to know him, and loved him like a son! He became the "black sheep" of our family!! People can change.
When my wife had our daughter, I made her middle name "Raye" in his honor. I always tell people she was named after a black guy.
Ignore the jerk, maybe he'll grow up someday, maybe not.
Don't waste your time worrying about it.