It's just like the general election where the electors you vote for have no actual obligation to side with the popular vote.

There is no Constitutional provision or Federal law that requires electors to vote according to the results of the popular vote in their States.

For the non-yanks, when you tick the box next to "Genocide Joe", you aren't actually voting for him, you're voting for the people who pinky promise to do so but aren't actually required to.