What emotion or ideal do you think keeps racism thriving so strongly?

I personally think it's the media left and right up and down that fuel that fire.. I bet every single person you stop and ask don't care wether someone's black white yellow green muzzo or Christian.. They just want everyone to be civil..

People being afraid to talk about race in an open an honest manner since people are like the Gestapo and police each other to make sure everything is PC.

if we really share day to day lives
really getting to know one another
we'd do different

Media and the lack of discipline. Toddlers are curious about other skin colors, while their parents could be like "don't play with him, because he's from Africa, but do play with kids of your own skin color", that's simply racism that comes from the parents, giving forth to the child... :(

I think that it's an innate dislike of something that's foreign to them and not willing to understand it... and then the media plays on this emotion.

Fear and hate , we would be better off without them

Good question.
I think xenophobia is more spread than racism nowadays. People are afraid of not having their part of the cake.
In the case of racism, I would add stereotypes showed and the idea that we all have to be and behave the same. The different is anormal and not evolved.

Unfamiliarity and constantly having out cultural differences rammed down our throats...

People are more alike across the world than most realise and the way to bring people together is to show them their similarities, not concentrate on how they are different.

fear

Fear.

vested interest