Why are so many obama supporters threatening to riot and cause crap if he loses?

[ZooDoo]

I've heard a lot of Pretty sad and disgusting things coming from Obama supporters The last couple months ( All the racist/hateful remarks towards stacy dash for example)

But there's a lot on Twitter threatening to riot, throw tantrums, and basically just act like spoiled brats and sore losers if Romney wins.... and yet I've heard nothing anywhere close from romney supporters if HE Loses