Standing up for what you believe in is not the same as taking a stance on a topic to achieve “moral authority”, although both goals are not necessarily mutually exclusive, and aggressive attempts to display “moral authority” only serve to expose an entities ultimate agenda and typically leads to exposure as a hypocrite or an outright charlatan. There are plenty of demagogues that come to mind when I think of that line of reasoning.
I don't see Palin acting aggressively to display moral authority.
True moral authority is earned. Through taking principled stances and working to better improve conditions Palin seems to be doing so as more and more people tune into and trust what she has to say.