Dan Quayle misspelled one word and he was ridiculed for 4 years and more, Obama has pilled up worse mistakes and MSM just wont touch it. Here is a opinion piece on Yahoo news that questions the same thing:
"Imagine that named a young running mate to campaign with him, and this national rookie suggested America had 58 states, repeatedly used the wrong names for the cities he was visiting, and honored a crowd by acknowledging the "fallen heroes" who were present, somehow alive and standing in the audience. How long would it take for the national media to see another caricature? Let's raise the stakes. What if it was the GOP making these thoroughly ridiculous comments? This scenario is very real, except it isn't McCain. It's the other fellow."