Most people associate “higher calling” to a command from God to do God’s work.
I question those who make that claim.
Sarah Palin was quoted as mentioning “higher calling” when quitting as governor yesterday.
I suppose if God truly called her she will win the presidency.
If not, she should check behind the voice to make sure who is calling who.

From the little I have seen as of this writing, Sarah Palin’s “higher calling” in her mind appears to be shorthand for her political agenda rather than specifically as a run for US President–lower taxes, less government, lower dependence on Middle East oil, and so on.
She is resigning her governorship in large measure (in my present understanding of what she says) because the political attacks against her are draining resources for the agenda she feels her governorship deserves.
In other words, she is choosing her battles; she can’t fight every one. But this assumes resignation will drop her lightning rod from a high place to a low one where there won’t be so many strikes.
If this view is true to Palin, I doubt that a run for the US presidency is what she has in mind. Why add hassles and lightning strikes?
But I sympathize with your skepticism of the “higher calling” claim. Experience has shown me such calls are often dripping with self-interest.
As to Palin’s calling … time will tell.
Hi Peter;
If your reading of it is true, and it may be, it will be to Palin’s credit regardless of what others say.
It is difficult to do a job when someone is questioning you ability to do it every day.