Given that California is generally considered one of the most liberal in the nation, and that the headline (or how he imagined it) is critical of the state in q

Given that California is generally considered one of the most liberal in the nation, and that the headline (or how he imagined it) is critical of the state in question, it's actually a very reasonable suspicion. Your assumption that he would not use a comparable term for the opposite situation, say "a liberal hit piece about Texas" in fact reveals a much more obvious lack of objectivity.