That's a good point. The difference is that 'jerk' is on its face a subjective assessment, an opinion, while 'racist' is less so. I have a feeling there's supreme court precedent drawing a more exact line.
Of course, devoid of context, 'racist' is pretty subjective as well. I'm guessing if the statements had been left sufficiently ambiguous, they might have gotten away with it. But they weren't - they accused them of a very specific racism, and demonstrated a reckless disregard for the truth.
From a quick search, looks like in cases such as these, the standard would be that the statements are made with 'actual malice' [1].
Edit: I noticed you asked what the law should be, not what it is. I guess I'm not so sure of the answer, but I'd venture that statements made with 'actual malice' should be included in libel.
Of course, devoid of context, 'racist' is pretty subjective as well. I'm guessing if the statements had been left sufficiently ambiguous, they might have gotten away with it. But they weren't - they accused them of a very specific racism, and demonstrated a reckless disregard for the truth.
From a quick search, looks like in cases such as these, the standard would be that the statements are made with 'actual malice' [1].
Edit: I noticed you asked what the law should be, not what it is. I guess I'm not so sure of the answer, but I'd venture that statements made with 'actual malice' should be included in libel.
[1] https://en.wikipedia.org/wiki/False_statements_of_fact#Priva...