When has media balance been balanced, historically?

Media balance is a political plaything, easy to point to, and then move on. Historically, it is hard to find balance as media is often partisan. In the US, Fox has been the most balanced in recent times, being centre right on most issues, Fox still has a number of journalists who report sympathetically to a left leaning audience as well. So, we can look at Fox advocacy in the recent past and see how they were both sides on the issue of Obama being elected in 2008, and 2012. But, what of other major networks, like ABC, NBC, CNN or CBS? What of their commentary on Obama opponents Romney and McCain? Where was their balance then? How has their rhetoric changed over time regarding the two now that they no longer wear the aegis leading the GOP?

In Australia, The rolling of Tony Abbott was similar to rolling of Gorton as PM. But compare it with the rolling of Fraser, or Turnbull, or Hawke and Rudd.

The behaviour of partisan press was evident in 1800's, when Nelson was a Whigg so "He could be heard."