This is the classic Fox News defense, and it somehow keeps working. Probably because the courts are packed with Republican judges and judges hold individuals to too high of a standard.
Yes, several people have made this comment, so I'll reply to all of them here. This is a version of the "Tucker Carlson" defense. However, it is being applied to wholly different kinds of statements.
The law of defamation applies to statements of fact, not statements of opinion. Example: Trump is a corrupt piece of shit, is an opinion. Trump pressured the Ukrainians to start an investigation of Biden, is a statement of fact.
Sometimes there can be a grey area where it isn't clear if the statement is one of opinion or fact. That was the case with Tucker Carlson. Carlson had said that Stacey McDougal was trying to "shake down" Trump when she sued him. That is speculation as to her motive, so it's a pretty borderline case.
By contrast, Sidney Powell made statements like: "Dominion's voting machines were hacked and this caused 60,000 votes to change from Trump to Biden in Michigan." You really can't get more factual than those statements. Also, Carlson is an opinion host with a reputation for partisan hyperbole. Not so Powell, who is a lawyer.
I seriously doubt she will prevail.