I make slurs about different races all the time. I was laughing really hard about the ear piercing comment in another thread that went along the lines of "only Mexicans pierce their little girls ears that young" that might not be true but I've only ever SEEN Mexican parents OBSESS over getting their daughters ears pierced, so it rang true to me, in a way.
I laugh at black jokes all the time - Sad thing is, I'm a very white girl who was raised by a black family.
Honestly I believe everyone is guilty of it at some point whether they admit it or not.
ETA: maybe not racism but definitely making the remarks or having the thoughts that could be called 'racist'