I would bet it was Obama that clinched it for him and turned a squeaker into a shutout. Nothing arouses nationalist spirit and makes the voters rally 'round the flag like having a very prominent foreigner, who seems to be intent on your ruin, visibly try to interfere with your election.
Obama and his advisers, despite pooh-poohing 'American exceptionalism,' are continually guilty of astoundingly arrogant parochial thinking themselves, and think that his undeserved popularity with American media extends to the population as a whole, not just here, but around the world.