Robert Parry said it for me.
The bottom line is this: When the American Right is offended, the “corrections” come fast and are sweeping, even in highly dubious situations. Sometimes heads roll.
But when the American Left feels aggrieved, the “corrections” are slow and grudging, often very narrow in scope and still misleading. Nobody is likely to get punished.
Parry cites egregious examples in The New York Times, The Washington Post, and at CBS.