As a reminder: Ronald Reagan finished his second term as Governor of California in January, 1975. He ran for the Presidency in 1976. I remember vividly, as I was a Reagan volunteer during his primary run. He did not resign the office of Governor, in his second term, in 1972 because he was going to run for the Presidency in 1976.
Be careful with your Reagan analogies. They aren't always favorable for Palin, no matter how much you wish them to be.
Reagan was also the focus of a smear campaign while serving as governor, and there was one unsuccessful attempt to have him removed. However, back then, people had the decency to focus their attacks on the man and not his family. Nor did Reagan have to endure Palin’s legal battles where she is deluged with frivolous lawsuits designed to distract her and drain her personal finances.