You nailed it. Now, if she endorses him for his next election, well, then....
I think that would show she was going beyond bounds at that point. She should let him do his thing and not be a dedicated cheer leader any more. I believe she did hope that she could elevate his world view, not just be a blind booster. And if she has wisdom she will see as that didn’t pan out too well, it’s her time to give him space.
She won't.
Fact is, I don't expect McCain to run for another term. Instead, I imagine that he will announce his retirement with a year-or-so left -- expecting the governor to appoint his prodigal child to the "family seat".
And, somehow, I can't imagine Sarah Palin having anything good to say about Miss Megan...