And most of the above, such as FiveThirtyEight, predicate their analysis on a comprehensive sampling of polls, including swing state polls, where the election will be decided.
It's interesting that the financial markets lag behind the poll probabilities. I think that's because the financial markets are less rational. With any "stock", people tend get a sort of emotional attachment to the stock. Instead of selling a loser off and taking the small hit, they'll ride it all the way to the bottom, in a vain hope of recouping the loss later.
That certainly explains your undying devotion to Obama.