Obama wins the election, but is impeached and convicted on charges of campaign finance fraud. I don't know if that rises to the level of "high crimes and misdemeanors," but I would think it should.
Joe Biden is set to ascend to the Presidency, but suffers a debilitating brain aneurysm before he can take the oath of office.
Nancy Pelosi becomes the first female president. Hillary Clinton spontaneously combusts.
This is where I wake up, because if Pelosi were ever to take over the presidency, we can kiss Western Civ goodbye.