Ah, but remember when Geraldine Ferraro was first put in front of reporters after Mundale picked her as his running mate?
The reporters started to ask some real questions, and Ferraro broke down in frustration, crying something akin to "But..., but..., but you're supposed to be on MY side!"
Between that, and Mudd taking out his good friend EM Kennedy in 1980 with the simple inquiry "Why do you want to be president" (and Mudd's subsequent elimination as a replacement for Cronkite), the "press" got in line with the Dems, as the difference in polls seems to indicate.
(Probably that, and the post-Watergate journalism types got seniority.)
That is one of the great interviews in election history, but I don't know if it reveals bias on the side of the reporter. It's actually the softballiest of softball questions to throw at a candidate. He couldn't have anticipated that Kennedy would stumble so badly.
Kennedy couldn't tell the truth, "Why, I'm a Kennedy! I deserve it," but he couldn't on the fly make up a nice sounding answer for the peasants either.
I recall TV "news" reporting -- I recall that there were days when nothing else was mentioned on the network news. They repeated charges against Nixon, et al. that had been new days ago.
It was a 24/7 frenzy.
.. and nary a word from the networks a few years earlier about the EXACT SAME THINGS (and worse) done during the JFK and LBJ administrations.
I worked with younger folks at the time and everyday they'd be repeating the latest TV network "news" about that "bastard" Nixon.