I actually think that it depends pretty much completely on the context. There is no list of phrases that are innocent or malicious in and of themselves. Something that can seem innoccuous in most situations can be a matter of life or death in others. So no, I don't think we seem to agree. And could you answer the question rather than dancing around it?

There can't be, because "jerk" is a subjective assessment, and defamation requires a statement of fact. The "falsifiability" rubric Rayiner has been using is helpful. I'm not a lawyer, but I read lots of defamation lawyers, and note that you can further extend the requirements for defamation:

* It's (apparently, in many circumstances, consult lawyer) not defamation to relate your interpretation of facts already on the record. In other words, it's often not defamation if you're simply wrong about something, so long as you're not relating your wrongness in a manner that would lead a reasonable person to think you're authoritative for your claim. "Based on a bunch of stuff I read in the paper, Gibson's has a history of racial profiling" might be a much safer thing to say than "as faculty and administrators of Oberlin College I'm informing you that Gibson's has a history of racial profiling".

* If the injured party is a "public figure", you have to do more than prove a falsifiable false statement that causes actual injury; you also have to prove malicious intent, meaning that the speaker knows that what they're saying is false, and is saying it specifically in order to harm someone.

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.

[1] https://en.wikipedia.org/wiki/False_statements_of_fact#Priva...

It would suck to live in a world where people can destroy your life by spreading lies about you, and you have no recourse. That's not the world we live in. What benefits do you think free-for-all slander and libel would give society exactly?

No need to imagine. There are countries where you would win.