SPLC attorneys said the First Amendment’s free speech guarantee protects opinions, so the organization cannot be held liable for defamation.
That's the same defense Facebook used to defend their "fact checkers". They do not state any facts, just protected opinions.
As I have repeatedly pointed out, our resident sniveling bitch "boy's" beloved left leaning media bias checker also uses the same "fact checkers" used by Facebook. As they use the same methods on both sites, then clearly they are just stating opinions, not facts.