As another poster has asked on this thread, please provide one example of a former presidential or vice-presidential candidate successfully suing for slander.
Palin isn't just a TV celebrity. She is a former VP candidate.
And if she is looking at running for office again, a lawsuit is basically out of bounds for her.
There are your abstract views. And then there are the realities of the situation. The reality is that McGinnis and other slimeballs like him can throw crap at Palin with impunity.
I never said it would be practical or effective to run the case for Palin. A good attorney predicts practical outcomes as against theoretical outcomes. So I don’t disagree that she is unlikely to pursue the case, and for the very reasons you cite. I am only pointing out that, contrary to the tone of your assertions, the law does indeed provide public figures with a practical means to protect their reputation, if they can meet the burden of proof, and if their life and career circumstances justify standing and fighting.
And the law for public figures is not an abstraction. It’s a question of effectiveness in a given case, for a given client. For Palin, I would advise her not to run the case, even if she had a smoking gun that solved her burden of proof. She may lose some small fraction of support for minimizing her response to these allegations, but she will gain much more elsewhere for focusing her campaign on what matters to the voters.