I don't want to exaggerate the magnitude of this, but I have come around to the notion that one of the factors, albeit perhaps a small one, that helps explain the bizarre behavior of mainstream journalists toward Republican scandal over the past quarter century is the sense that the press corps owes one to the GOP after Watergate.
The scandal was the one instance in American history where a president was forced to resign and investigative journalism was arguably the main driver. The press aggressively pursued the story and the coverage was, at the very least, sometimes colored by the personal dislike that many journalists felt toward Nixon.
As the years passed and the former president (deservedly or not) manage to rehabilitate some of his reputation, the idea seemed to take root in the press corps that they needed to balance the scales. The idea was nurtured by the Republicans and conservative media but I don't believe it was planted by them. Like its sister belief, the biased liberal media theory, it was an idea born of and trapped in the 70s.
The Iran Contra scandal was both symptom and aggravating factor. There were hesitation marks all over the reporting, and while some of these can be attributed to the extraordinary popularity and charisma of Ronald Reagan, the timidity of the press is still notable. Nonetheless, despite the relatively gentle handling, it was still another case of journalists pursuing a Republican scandal.
By comparison, the election of Bill Clinton seemed to represented almost a perfect opportunity to balance things out. Not only was Clinton a Democrat, he also was an outsider (which threatened the livelihood of veteran reporters whose status rested on their DC Rolodexes) and a Southern boy from the wrong side of the tracks (which played on deep-seated regional and, more importantly, class prejudices).
I was in or around Arkansas through the 90s and I remember a constant sense of amazement. Perhaps it was just my naivety, but I was completely unprepared for how low supposedly respectable journalists were willing to go once they'd committed to a narrative, even if it meant crawling in bed with the remnants of the state's segregationist movement (I still remember my revulsion seeing the Washington press corps elevate Jim Johnson to elder statesman).
I've argued before that the bad journalism that took root during Whitewater was a contributing factor and possibly necessary condition for the Bush presidency, the build-up to Iraq, and a general undermining of democracy that culminated with the election of Donald Trump. It would be ironicc if misplaced guilt over great journalism helped contribute to the decline of the profession.
For related oints, check out thee following from Charles Pierce and Frontline.