Gonna start a pool. There's no pot, it's just for A) shits and giggles, and B) to hopefully provoke a more serious discussion.
Right then: racism is still rife in the US, the UK and rather a lot of other countries in the global north. Divide and rule has it's claws in deep. Barack Obama is the US's first non-white president (he's not black btw, he's mixed-race.) Not everybody is gonna take kindly to having a man of mixed ethnicity running a country where a not inconsiderable number of people still feel that racism is a god-given right.
So, how long until some zealous nutjob shoots him? It doesn't have to be fatal, but the bullet does have to come within one metre of his skin. I'm gonna say 12 months. Any other takers?