I certainly agree that media bias can and does have some affect on voting. What I don't agree on is that the effect is necessarily more pronounced in democratic/liberal voters.
Benghazi has been a major news story for many many months now so I wouldn't say they are avoiding it. There is a legitimate disagreement about the significance of it though and that is not purely a matter of political bias. If it were up to the current administration, there would be no coverage from anyone about Benghazi. Again, I don't disagree with you that the major media outlets as a whole are not living up to a high standard of journalistic excellence, I just disagree that the cause is primarily a political agenda.
Yes, what you say about whistle blowers is true but whistle blowers have always been a major source for such news. I disagree that the media was lying to us before about say the NSA program. They were simply ignorant. Once a whistle blower emerged, they covered the story quite extensively. It is still a top topic in the mainstream media months after the story broke.
As the article discusses though, some of the reason for that was due to horse-race coverage. Obama was leading in many polls so simply reporting those polls was taken as positive coverage for Obama and negative for Romney. This is not bias though. Now this does not say the trend doesn't clearly imply some bias, but it is not as skewed as the raw data would make you believe. It's also important to note that they compare Fox to MSNBC at the same time and you see a very similar skewing in the opposite direction. So if you ignore the very legitimate reasons why Obama might be getting more favorable coverage in the last week, how do you account for Fox's anti-Obama bias (as clear as MSNBC's) and still say the mainstream media has an Obama bias.
You answered your own question as to why the press isn't asking hard questions. But not wanting to jeapordize their access is not the same as being in love with the Obama administration.
I agree except I'm not sure why the "liberal media" would have an increased effect. Fox is the most watched news network in the country and it has a clear right wing bias as supported by both articles you posted earlier.