There's a myth that Dan Rather was fired because of Rathergate (also called Memogate or the Killian documents controversy), but I think that ignores a lifetime of other incompetence.
Far left polemic Dan Rather tried to rig an election by running a timed Bush hit piece on 60 minutes, just before the 2004 election, using shoddy and unvetted "Killian documents" which claimed that Bush was incompetent, insubordinate and didn't complete his National Guard Service in 1973. The Internet decomposed the typography and showed the forgery within hours, and commanders and folks involved refuted the accounts, and Dan Rather, some of his staff, and even some execs had to reluctantly be fired for journalistic fraud and incompetence. more...
I don't think anyone can know if CBS fired Dan for this sloppiness, or fear of the next one (and the whole truth coming out). It helps to remember a few of the others, as reported in Alan Weisman's excellent book, "Lone Star: The Extraordinary Life and Times of Dan Rather". Some scandals covered include the following:
- 1963 Dallas, being the first to report on the death of JFK. He had heard it from a Priest, and before getting verification had fumbled telling the CBS Control Room about it, and it was blasted on the air before verification. He was accidentally right, and got his career started by breaking a story he should have never broke.
- 1969 he broke the story that President Nixon was about to fire J. Edgar Hoover, who stayed on until his death, 3 years later.
- 1969 he botched a story about Nixon preparing to fire a top Vietnam official... that also never happened.
- 1963-1974 He was obviously anti-America and anti-Vietnam war, and told the Vietcong's side of the story nightly, which is fine if you're a civilian, but not if you're playing an unbiased Newsman on TV.
- 1980 "Gunga Dan" did a 60 Minutes segment dressed up in mujahideen-wear while in Afghanistan, that was mocked like the Brian Williams, "I was there" lie.
- Timothy Crouse wrote in his chronicle of campaign reporters (The Boys on the Bus), that Rather was hated by other reporters because he would regularly run rumors as news when covering the Whitehouse. He not only embarrassed them, but usually got away with it: lowering their craft.
- Once he ignominiously was exited from CBS, he went on to being a 3rd string op-ed guy on AXS TV (a cable channel few have heard of). But he puts on his activist hat with anti-Trump and anti-Sanity rants on Facebook and twitter, which makes him a darling of the far left, but reminds the informed of how "unbiased" he's been all along.
The guy's career has been a parody of Ron Burgundy, if Ron was less competent, less self-aware and even more self-centered.