Hmmmm....I guess you missed these:
In the years after Reagan was Governor, he gave far more speeches and made many more campaign appearances, along with writing and delivering more than a thousand short format radio commentaries. Thatcher had an astonishing work ethic that flummoxed Conservative Party adversaries who tried to overburden her with a combination of Parliamentary duties and public appearances.
In that manner, Reagan and Thatcher became polished and deeply knowledgeable speakers with an ability to not just fire up friendly audiences but to win converts. In 1975, I saw Reagan Reagan speak before deeply skeptical college students and win many of them over, with hard Leftists rattled by his appeal. Similarly, Melanie Phillips has recounted how listening to Thatcher's speeches helped make her into a conservative, so impressed was Phillips by Thatcher's sincerity and forceful reasoning that resonated with her misgivings over the effect of Leftism on British family life.
So far, Palin has not seemed to be able to reach beyond her fan base, and she has not established herself as having a wide range of expertise on the issues. Unless Palin can do so, she will not be an effective candidate for President.