Fox has become so integral to national Republican politics that senior campaign staffers freely talk about its unique role in campaign strategy. Presumably other cable or broadcast networks could also provide a comparatively “sedate” environment for a candidate looking to escape the “frenzy” of the traveling press, but they chose Fox for a reason. For candidates like Romney, Fox is a sanctuary from the rest of the media where the candidate’s message can get out there without anyone challenging it.
Counterpoint:” it’s not like MSNBC has clean hands either: MSNBC more biased than Fox News
Image source and article: http://mediamatters.org/blog/2013/09/05/fox-news-where-republicans-go-to-escape-journal/195727