Why would it show up now if it didn’t show up in 2008?
I’m not convinced it didn’t show up in 2008.
In 2008 there was almost only one reason the effect was evident.
In 2012 there are more reasons. People still don’t want to be labeled racist [existed in 2008] but now they also do not want to be ridiculed, they don’t want to argue, they don’t want to even discuss. This is especially true for the slice of voters who previously voted for 0bama but will change.
That’s why.