Democrats = Action .... Republicans = Reaction
Democratic ideology is predicated on mans desire to improve the human condition. Society is not ... or should not be, a static thing. It is not realistic to suppose that society, in its current state, cannot be improved upon. Democrats basically, see making changes to society so that its benefits are available to more people, generally by enabling more opportunity for greater participation in the economy, as a desirable thing. Democrats feel this can rightly be called progress.
Republicans on the other hand, represent the forces opposed to any change. These forces generally emanate from those who enjoy the most power and wealth in society. But these forces also come from those found in any society who are impaired by ignorance (who generally fear change of any kind). Consequently, virtually all the ideas or theories proposed by the Conservatives are specious: fabricated to stand in opposition to ideas proposed by Democrats. These theories that Conservatives propose start out with the purpose or objective of contradicting a contention of a needed action - usually proposed by Democrats - but just as frequently proposed by social scientists who, coincidentally share with Democrats, the objective of wanting to make society work better for more people (I guess Conservatives would say, right there(!), the social scientists, by believing in that objective, are guilty of being partisans - of being Democrats.
This makes the Conservative contention that the media is biased.. by definition against the Conservatives - the biggest of the Big Lies, or at least the biggest example of Disinformation, promulgated by the Conservatives. While Conservatives constantly chant the media is biased against them, it is the Conservatives who propose theories predicated upon or designed solely to contradict or appear to disprove Democratic proposed ideas/solutions. It is the Conservatives who are proposing theories/ideas which are NOT the result of an open minded, logical analysis of the relevant facts, but which start with the objective of DIS-proving a proposed solution to a problem offered by Democrats.