I didn't mention Kerry. But if I recall correctly, he was doing well in polling among Democrats (re: the 2008 nomination) after losing in '04. My point is that Palin's popularity is based on name-recognition, and the fact that she's a lightning rod for criticism by liberals, more than anything else. I doubt she'll be there in 2012. I don't even think she'll end up running. To be honest with you, I haven't heard anything from her since Election Day, except for interviews about her perceived treatment by the media. You don't offer any evidence that she's the de facto head of the party.
She's been giving rounds of interviews and filming a DVD that argues Obama won because the media gave it to him. I agree, she's not the de facto head of the GOP right now, because she's in Alaska and there's only so much she can do from there, and elected Republican governors and members of Congress don't like her. Lord knows, she's trying. The evidence for her influence is the poll showing a majority of Republicans believe the party should be more like her. I think everyone can agree that's a bad idea. It shows that she is a threat and has massive dormant support in the party. In effect, she's the real version of what some Republicans wanted to believe Al Sharpton was about five years ago. But she is absolutely not calling the shots now. As I said, dormant right now, and capable of being supplanted by someone who captures the imagination of the base. I just don't know who that person would be. It's not Romney.
Rush Limbaugh does have the power to police Republican members of Congress that Markos Moulitsas wants, but doesn't have. He's smart enough to deploy it carefully but I think he is the main person setting the Republican message right now and administering discipline to those who go off the reservation. This reflects both his own strength in the media and decimation of Republicans in Washington.