Facebook announced last week that they will be mining your posts and messages for your thoughts on the GOP presidential candidates, and they will share that info with Politico.
From that announcement:
"Facebook will compile mentions of the candidates in U.S. users' posts and comments as well as assess positive and negative sentiments expressed about them. Facebook’s data team will use automated software tools frequently used by researchers to infer sentiment from text."
As an example of the kind of data this mining will reveal, they offer this. Here are some screenshots: